* Added loglevel parameter to logg()
* Fix logg and mprintf internals with new loglevels
* Update all logg calls to set loglevel
* Update all mprintf calls to set loglevel
* Fix hidden logg calls
* Executed clam-format
Convert cli_dbgmsg to inline function to ensure ctx check for debug flag
is always run
Add copyright and licensing info
Fix valgrind uninitialized buffer issue in cliunzip.c
Windows build fix
CID 361074: fmap.c: Possible invalid dereference if status != success
and the new map was not yet allocated.
CID 361077: others.c: Structurally dead code revealed a bug in the
cli_recursion_stack_get_size() function.
CID 361080, 361078, 361083: sigtool.c: Inverted check for if engine
needs to be free'd, could leak the engine structure.
CID 361075: sigtool.c: Missed a `return -1` that should've been `goto
done;` and would leak the new_map buffer.
CID 361079: sigtool/vba.c: Checking if we should free the new_map on
failure only if ctx also needs to be free'd, which would leak the
new_map if ctx was not allocated yet.
The previous commit broke alerting when exceeding the recursion limit
because recursion tracking is so effective that by limiting the final
layer of recursion to a scan of the fmap, we prevented it from ever
hitting the recursion limit.
This commit removes that restriction where it only does an fmap scan
(aka "raw scan") of files that are at their limit so that we can
actually hit the recursion limit and alert as intended.
Also tidied up the cache_clean check so it checks the
`fmap->dont_cache_flag` at the right point (before caching) instead of
before setting the "CLEAN" verdict.
Note: The `cache_clean` variable appears to be used to record the clean
status so the `ret` variable can be re-used without losing the verdict.
This is of course only required because the verdict is stored in the
error enum. *cough*
Also fixed a couple typos.
The fmap module provides a mechanism for creating a mapping into an
existing map at an offset and length that's used when a file is found
with an uncompressed archive or when embedded files are found with
embedded file type recognition in scanraw(). This is the
"fmap_duplicate()" function. Duplicate fmaps just reference the original
fmap's 'data' or file handle/descriptor while allowing the caller to
treat it like a new map using offsets and lengths that don't account for
the original/actual file dimensions.
fmap's keep track of this with m->nested_offset & m->real_len, which
admittedly have confusing names. I found incorrect uses of these in a
handful of locations. Notably:
- In cli_magic_scan_nested_fmap_type().
The force-to-disk feature would have been checking incorrect sizes and
may have written incorrect offsets for duplicate fmaps.
- In XDP parser.
- A bunch of places from the previous commit when making dupe maps.
This commit fixes those and adds lots of documentation to the fmap.h API
to try to prevent confusion in the future.
nested_offset should never be referenced outside of fmap.c/h.
The fmap_* functions for accessing or reading map data have two
implementations, mem_* or handle_*, depending the data source.
I found issues with some of these so I made a unit test that covers each
of the functions I'm concerned about for both types of data sources and
for both original fmaps and nested/duplicate fmaps.
With the tests, I found and fixed issues in these fmap functions:
- handle_need_offstr(): must account for the nested_offset in dupe maps.
- handle_gets(): must account for nested_offset and use len & real_len
correctly.
- mem_need_offstr(): must account for nested_offset in dupe maps.
- mem_gets(): must account for nested_offset and use len & real_len
correctly.
Moved CDBRANGE() macro out of function definition so for better
legibility.
Fixed a few warnings.
Scan recursion is the process of identifying files embedded in other
files and then scanning them, recursively.
Internally this process is more complex than it may sound because a file
may have multiple layers of types before finding a new "file".
At present we treat the recursion count in the scanning context as an
index into both our fmap list AND our container list. These two lists
are conceptually a part of the same thing and should be unified.
But what's concerning is that the "recursion level" isn't actually
incremented or decremented at the same time that we add a layer to the
fmap or container lists but instead is more touchy-feely, increasing
when we find a new "file".
To account for this shadiness, the size of the fmap and container lists
has always been a little longer than our "max scan recursion" limit so
we don't accidentally overflow the fmap or container arrays (!).
I've implemented a single recursion-stack as an array, similar to before,
which includes a pointer to each fmap at each layer, along with the size
and type. Push and pop functions add and remove layers whenever a new
fmap is added. A boolean argument when pushing indicates if the new layer
represents a new buffer or new file (descriptor). A new buffer will reset
the "nested fmap level" (described below).
This commit also provides a solution for an issue where we detect
embedded files more than once during scan recursion.
For illustration, imagine a tarball named foo.tar.gz with this structure:
| description | type | rec level | nested fmap level |
| ------------------------- | ----- | --------- | ----------------- |
| foo.tar.gz | GZ | 0 | 0 |
| └── foo.tar | TAR | 1 | 0 |
| ├── bar.zip | ZIP | 2 | 1 |
| │ └── hola.txt | ASCII | 3 | 0 |
| └── baz.exe | PE | 2 | 1 |
But suppose baz.exe embeds a ZIP archive and a 7Z archive, like this:
| description | type | rec level | nested fmap level |
| ------------------------- | ----- | --------- | ----------------- |
| baz.exe | PE | 0 | 0 |
| ├── sfx.zip | ZIP | 1 | 1 |
| │ └── hello.txt | ASCII | 2 | 0 |
| └── sfx.7z | 7Z | 1 | 1 |
| └── world.txt | ASCII | 2 | 0 |
(A) If we scan for embedded files at any layer, we may detect:
| description | type | rec level | nested fmap level |
| ------------------------- | ----- | --------- | ----------------- |
| foo.tar.gz | GZ | 0 | 0 |
| ├── foo.tar | TAR | 1 | 0 |
| │ ├── bar.zip | ZIP | 2 | 1 |
| │ │ └── hola.txt | ASCII | 3 | 0 |
| │ ├── baz.exe | PE | 2 | 1 |
| │ │ ├── sfx.zip | ZIP | 3 | 1 |
| │ │ │ └── hello.txt | ASCII | 4 | 0 |
| │ │ └── sfx.7z | 7Z | 3 | 1 |
| │ │ └── world.txt | ASCII | 4 | 0 |
| │ ├── sfx.zip | ZIP | 2 | 1 |
| │ │ └── hello.txt | ASCII | 3 | 0 |
| │ └── sfx.7z | 7Z | 2 | 1 |
| │ └── world.txt | ASCII | 3 | 0 |
| ├── sfx.zip | ZIP | 1 | 1 |
| └── sfx.7z | 7Z | 1 | 1 |
(A) is bad because it scans content more than once.
Note that for the GZ layer, it may detect the ZIP and 7Z if the
signature hits on the compressed data, which it might, though
extracting the ZIP and 7Z will likely fail.
The reason the above doesn't happen now is that we restrict embedded
type scans for a bunch of archive formats to include GZ and TAR.
(B) If we scan for embedded files at the foo.tar layer, we may detect:
| description | type | rec level | nested fmap level |
| ------------------------- | ----- | --------- | ----------------- |
| foo.tar.gz | GZ | 0 | 0 |
| └── foo.tar | TAR | 1 | 0 |
| ├── bar.zip | ZIP | 2 | 1 |
| │ └── hola.txt | ASCII | 3 | 0 |
| ├── baz.exe | PE | 2 | 1 |
| ├── sfx.zip | ZIP | 2 | 1 |
| │ └── hello.txt | ASCII | 3 | 0 |
| └── sfx.7z | 7Z | 2 | 1 |
| └── world.txt | ASCII | 3 | 0 |
(B) is almost right. But we can achieve it easily enough only scanning for
embedded content in the current fmap when the "nested fmap level" is 0.
The upside is that it should safely detect all embedded content, even if
it may think the sfz.zip and sfx.7z are in foo.tar instead of in baz.exe.
The biggest risk I can think of affects ZIPs. SFXZIP detection
is identical to ZIP detection, which is why we don't allow SFXZIP to be
detected if insize of a ZIP. If we only allow embedded type scanning at
fmap-layer 0 in each buffer, this will fail to detect the embedded ZIP
if the bar.exe was not compressed in foo.zip and if non-compressed files
extracted from ZIPs aren't extracted as new buffers:
| description | type | rec level | nested fmap level |
| ------------------------- | ----- | --------- | ----------------- |
| foo.zip | ZIP | 0 | 0 |
| └── bar.exe | PE | 1 | 1 |
| └── sfx.zip | ZIP | 2 | 2 |
Provided that we ensure all files extracted from zips are scanned in
new buffers, option (B) should be safe.
(C) If we scan for embedded files at the baz.exe layer, we may detect:
| description | type | rec level | nested fmap level |
| ------------------------- | ----- | --------- | ----------------- |
| foo.tar.gz | GZ | 0 | 0 |
| └── foo.tar | TAR | 1 | 0 |
| ├── bar.zip | ZIP | 2 | 1 |
| │ └── hola.txt | ASCII | 3 | 0 |
| └── baz.exe | PE | 2 | 1 |
| ├── sfx.zip | ZIP | 3 | 1 |
| │ └── hello.txt | ASCII | 4 | 0 |
| └── sfx.7z | 7Z | 3 | 1 |
| └── world.txt | ASCII | 4 | 0 |
(C) is right. But it's harder to achieve. For this example we can get it by
restricting 7ZSFX and ZIPSFX detection only when scanning an executable.
But that may mean losing detection of archives embedded elsewhere.
And we'd have to identify allowable container types for each possible
embedded type, which would be very difficult.
So this commit aims to solve the issue the (B)-way.
Note that in all situations, we still have to scan with file typing
enabled to determine if we need to reassign the current file type, such
as re-identifying a Bzip2 archive as a DMG that happens to be Bzip2-
compressed. Detection of DMG and a handful of other types rely on
finding data partway through or near the ned of a file before
reassigning the entire file as the new type.
Other fixes and considerations in this commit:
- The utf16 HTML parser has weak error handling, particularly with respect
to creating a nested fmap for scanning the ascii decoded file.
This commit cleans up the error handling and wraps the nested scan with
the recursion-stack push()/pop() for correct recursion tracking.
Before this commit, each container layer had a flag to indicate if the
container layer is valid.
We need something similar so that the cli_recursion_stack_get_*()
functions ignore normalized layers. Details...
Imagine an LDB signature for HTML content that specifies a ZIP
container. If the signature actually alerts on the normalized HTML and
you don't ignore normalized layers for the container check, it will
appear as though the alert is in an HTML container rather than a ZIP
container.
This commit accomplishes this with a boolean you set in the scan context
before scanning a new layer. Then when the new fmap is created, it will
use that flag to set similar flag for the layer. The context flag is
reset those that anything after this doesn't have that flag.
The flag allows the new recursion_stack_get() function to ignore
normalized layers when iterating the stack to return a layer at a
requested index, negative or positive.
Scanning normalized extracted/normalized javascript and VBA should also
use the 'layer is normalized' flag.
- This commit also fixes Heuristic.Broken.Executable alert for ELF files
to make sure that:
A) these only alert if cli_append_virus() returns CL_VIRUS (aka it
respects the FP check).
B) all broken-executable alerts for ELF only happen if the
SCAN_HEURISTIC_BROKEN option is enabled.
- This commit also cleans up the error handling in cli_magic_scan_dir().
This was needed so we could correctly apply the layer-is-normalized-flag
to all VBA macros extracted to a directory when scanning the directory.
- Also fix an issue where exceeding scan maximums wouldn't cause embedded
file detection scans to abort. Granted we don't actually want to abort
if max filesize or max recursion depth are exceeded... only if max
scansize, max files, and max scantime are exceeded.
Add 'abort_scan' flag to scan context, to protect against depending on
correct error propagation for fatal conditions. Instead, setting this
flag in the scan context should guarantee that a fatal condition deep in
scan recursion isn't lost which result in more stuff being scanned
instead of aborting. This shouldn't be necessary, but some status codes
like CL_ETIMEOUT never used to be fatal and it's easier to do this than
to verify every parser only returns CL_ETIMEOUT and other "fatal
status codes" in fatal conditions.
- Remove duplicate is_tar() prototype from filestypes.c and include
is_tar.h instead.
- Presently we create the fmap hash when creating the fmap.
This wastes a bit of CPU if the hash is never needed.
Now that we're creating fmap's for all embedded files discovered with
file type recognition scans, this is a much more frequent occurence and
really slows things down.
This commit fixes the issue by only creating fmap hashes as needed.
This should not only resolve the perfomance impact of creating fmap's
for all embedded files, but also should improve performance in general.
- Add allmatch check to the zip parser after the central-header meta
match. That way we don't multiple alerts with the same match except in
allmatch mode. Clean up error handling in the zip parser a tiny bit.
- Fixes to ensure that the scan limits such as scansize, filesize,
recursion depth, # of embedded files, and scantime are always reported
if AlertExceedsMax (--alert-exceeds-max) is enabled.
- Fixed an issue where non-fatal alerts for exceeding scan maximums may
mask signature matches later on. I changed it so these alerts use the
"possibly unwanted" alert-type and thus only alert if no other alerts
were found or if all-match or heuristic-precedence are enabled.
- Added the "Heuristics.Limits.Exceeded.*" events to the JSON metadata
when the --gen-json feature is enabled. These will show up once under
"ParseErrors" the first time a limit is exceeded. In the present
implementation, only one limits-exceeded events will be added, so as to
prevent a malicious or malformed sample from filling the JSON buffer
with millions of events and using a tonne of RAM.
Xcode (and perhaps some other generators?) do not like targets that have
only object files. See:
https://cmake.org/cmake/help/latest/command/add_library.html#object-libraries
And: https://cmake.org/pipermail/cmake/2016-May/063479.html
This issue manifests when using `-G Xcode` on macOS as the library
dylibs being missing when linking with other binaries.
This commit removes the object libraries for libclamav, libfreshclam,
libclamunrar_iface, libclamunrar, libclammspack, and (lib)common
because they were used by static or shared libs that didn't
themselves have any added sources.
Add getter & setter for the debug flag, so it isn't referenced by unit
tests or other code that links with libclamav. This is needed because
global variables are exported symbols on Windows.
Add progress callbacks to libclamav for:
- database load
- engine compile
- engine free
Add a progress bar to clamscan for load & compile.
These are disabled if you run with --debug or stdout is not a TTY or you
are using one of --quiet, --infected, or --no-summary.
Added code so you can test the engine-free callback by building with
ENABLE_ENGINE_FREE_PROGRESSBAR defined.
The compile & free progress callbacks pre-calculate the number of
tasks to complete to estimate the progress. Some tasks may take longer
than others so the progress speed my appear to vary a little.
The callbacks return type is a cl_error_t but doesn't currently do
anything. It is reserved for future use.
Minor formatting change in matcher-ac.c to counteract weird
clang-format behavior, and to make it easier to read.
Added progress callbacks and clamscan progress bars to the news.
CMake is now required to build.
The built-in LLVM is no longer available.
Also removed support for libltdl calls, which is not used in the CMake
builds, was only used when building with Autotools.
TODO: Fix CMake LLVM support & update to work with modern versions.
The previous UnRAR vuln fix worked for the (old, gone) Visual Studio
solution but broke the CMake build. We didn't notice because we tested
and approved it with Visual Studio before switching to CMake.
This change switches it to use the correct macro for the
libclamunrar_iface extension which is ".dll" instead of "lib".
Enabled the metadata collection feature, scan heuristics, and all-match
mode when fuzzing in the interest of better code coverage.
Also remove deprecated STREAM command.
An ENABLE_TESTS CMake option is provided so that users can disable
testing if they don't want it. Instructions for how to use this
included in the INSTALL.cmake.md file.
If you run `ctest`, each testcase will write out a log file to the
<build>/unit_tests directory.
As with Autotools' make check, the test files are from test/.split
and unit_tests/.split files, but for CMake these are generated at
build time instead of at test time.
On Posix systems, sets the LD_LIBRARY_PATH so that ClamAV-compiled
libraries can be loaded when running tests.
On Windows systems, CTest will identify and collect all library
dependencies and assemble a temporarily install under the
build/unit_tests directory so that the libraries can be loaded when
running tests.
The same feature is used on Windows when using CMake to install to
collect all DLL dependencies so that users don't have to install them
manually afterwards.
Each of the CTest tests are run using a custom wrapper around Python's
unittest framework, which is also responsible for finding and inserting
valgrind into the valgrind tests on Posix systems.
Unlike with Autotools, the CMake CTest Valgrind-tests are enabled by
default, if Valgrind can be found. There's no need to set VG=1.
CTest's memcheck module is NOT supported, because we use Python to
orchestrate our tests.
Added a bunch of Windows compatibility changes to the unit tests.
These were primarily changing / to PATHSEP and making adjustments
to use Win32 C headers and ifdef out the POSIX ones which aren't
available on Windows. Also disabled a bunch of tests on Win32
that don't work on Windows, notably the mmap ones and FD-passing
(i.e. FILEDES) ones.
Add JSON_C_HAVE_INTTYPES_H definition to clamav-config.h to eliminate
warnings on Windows where json.h is included after inttypes.h because
json-c's inttypes replacement relies on it.
This is a it of a hack and may be removed if json-c fixes their
inttypes header stuff in the future.
Add preprocessor definitions on Windows to disable MSVC warnings about
CRT secure and nonstandard functions. While there may be a better
solution, this is needed to be able to see other more serious warnings.
Add missing file comment block and copyright statement for clamsubmit.c.
Also change json-c/json.h include filename to json.h in clamsubmit.c.
The directory name is not required.
Changed the hash table data integer type from long, which is poorly
defined, to size_t -- which is capable of storing a pointer. Fixed a
bunch of casts regarding this variable to eliminate warnings.
Fixed two bugs causing utf8 encoding unit tests to fail on Windows:
- The in_size variable should be the number of bytes, not the character
count. This was was causing the SHIFT_JIS (japanese codepage) to UTF8
transcoding test to only transcode half the bytes.
- It turns out that the MultiByteToWideChar() API can't transcode
UTF16-BE to UTF16-LE. The solution is to just iterate over the buffer
and flip the bytes on each uint16_t. This but was causing the UTF16-BE
to UTF8 tests to fail.
I also split up the utf8 transcoding tests into separate tests so I
could see all of the failures instead of just the first one.
Added a flags parameter to the unit test function to open testfiles
because it turns out that on Windows if a file contains the \r\n it will
replace it with just \n if you opened the file as a text file instead of
as binary. However, if we open the CBC files as binary, then a bunch of
bytecode tests fail. So I've changed the tests to open the CBC files in
the bytecode tests as text files and open all other files as binary.
Ported the feature tests from shell scripts to Python using a modified
version of our QA test-framework, which is largely compatible and will
allow us to migrate some QA tests into this repo. I'd like to add GitHub
Actions pipelines in the future so that all public PR's get some testing
before anyone has to manually review them.
The clamd --log option was missing from the help string, though it
definitely works. I've added it in this commit.
It appears that clamd.c was never clang-format'd, so this commit also
reformats clamd.c.
Some of the check_clamd tests expected the path returned by clamd to
match character for character with original path sent to clamd. However,
as we now evaluate real paths before a scan, the path returned by clamd
isn't going to match the relative (and possibly symlink-ridden) path
passed to clamdscan. I fixed this test by changing the test to search
for the basename: <signature> FOUND within the response instead of
matching the exact path.
Autotools: Link check_clamd with libclamav so we can use our utility
functions in check_clamd.c.
Users have complained about two specific log events that are extremely
verbose in non-critical error conditions:
- clamonacc reports "ERROR: Can't send to clamd: Bad address"
This may occur when small files are created/destroyed before they can
be sent to be scanned. The log message probably should only be
reported in verbose mode.
- clamonacc reports "ClamMisc: $/proc/XXX vanished before UIDs could be
excluded; scanning anyway"
This may occur when a process that accessed a file exits before
clamonacc find out who accessed the file. This is a fairly frequent
occurence. It can still be problematic if `clamd` was the process which
accessed the file (like a clamd temp file if watching /tmp), generally
it's not an issue and we want to silently scan it anyways.
Also addressed copypaste issue in onas_send_stream() wherein fd is set
to 0 (aka STDIN) if the provided fd == 0 (should've been -1 for invalid
FD) and if filename == NULL. In fact clamonacc never scans STDIN so the
scan should fail if filename == NULL and the provided FD is invalid
(-1).
I also found that "Access denied. ERROR" is easily provoked when using
--fdpass or --stream using this simple script:
for i in {1..5000}; do echo "blah $i" > tmp-$i && rm tmp-$i; done
Clamdscan does not allow for scans to fail quietly because the file does
not exist, but for clamonacc it's a common thing and we don't want to
output an error. To solve this, I changed it so a return length of -1
will still result in an "internal error" message but return len 0
failures will be silently ignored.
I've added a static variable to onas_client_scan() that keeps state in
case clamd is stopped and started - that way it won't print an error
message for every event when offline. Instead it will log an error for
the first connection failure, and log again when the connection is
re-established for a future scan. Calls to onas_client_scan() are
already wrapped with the onas_scan_lock mutex so the static variable
should be safe.
Finally, there were a couple of error responses from clamd that can
occur if the file isn't found which we want to silently ignore, so I've
tweaked the code which checks for specific error messages to account for
these.
This patch adds experimental-quality CMake build tooling.
The libmspack build required a modification to use "" instead of <> for
header #includes. This will hopefully be included in the libmspack
upstream project when adding CMake build tooling to libmspack.
Removed use of libltdl when using CMake.
Flex & Bison are now required to build.
If -DMAINTAINER_MODE, then GPERF is also required, though it currently
doesn't actually do anything. TODO!
I found that the autotools build system was generating the lexer output
but not actually compiling it, instead using previously generated (and
manually renamed) lexer c source. As a consequence, changes to the .l
and .y files weren't making it into the build. To resolve this, I
removed generated flex/bison files and fixed the tooling to use the
freshly generated files. Flex and bison are now required build tools.
On Windows, this adds a dependency on the winflexbison package,
which can be obtained using Chocolatey or may be manually installed.
CMake tooling only has partial support for building with external LLVM
library, and no support for the internal LLVM (to be removed in the
future). I.e. The CMake build currently only supports the bytecode
interpreter.
Many files used include paths relative to the top source directory or
relative to the current project, rather than relative to each build
target. Modern CMake support requires including internal dependency
headers the same way you would external dependency headers (albeit
with "" instead of <>). This meant correcting all header includes to
be relative to the build targets and not relative to the workspace.
For example, ...
```c
include "../libclamav/clamav.h"
include "clamd/clamd_others.h"
```
... becomes:
```c
// libclamav
include "clamav.h"
// clamd
include "clamd_others.h"
```
Fixes header name conflicts by renaming a few of the files.
Converted the "shared" code into a static library, which depends on
libclamav. The ironically named "shared" static library provides
features common to the ClamAV apps which are not required in
libclamav itself and are not intended for use by downstream projects.
This change was required for correct modern CMake practices but was
also required to use the automake "subdir-objects" option.
This eliminates warnings when running autoreconf which, in the next
version of autoconf & automake are likely to break the build.
libclamav used to build in multiple stages where an earlier stage is
a static library containing utils required by the "shared" code.
Linking clamdscan and clamdtop with this libclamav utils static lib
allowed these two apps to function without libclamav. While this is
nice in theory, the practical gains are minimal and it complicates
the build system. As such, the autotools and CMake tooling was
simplified for improved maintainability and this feature was thrown
out. clamdtop and clamdscan now require libclamav to function.
Removed the nopthreads version of the autotools
libclamav_internal_utils static library and added pthread linking to
a couple apps that may have issues building on some platforms without
it, with the intention of removing needless complexity from the
source. Kept the regular version of libclamav_internal_utils.la
though it is no longer used anywhere but in libclamav.
Added an experimental doxygen build option which attempts to build
clamav.h and libfreshclam doxygen html docs.
The CMake build tooling also may build the example program(s), which
isn't a feature in the Autotools build system.
Changed C standard to C90+ due to inline linking issues with socket.h
when linking libfreshclam.so on Linux.
Generate common.rc for win32.
Fix tabs/spaces in shared Makefile.am, and remove vestigial ifndef
from misc.c.
Add CMake files to the automake dist, so users can try the new
CMake tooling w/out having to build from a git clone.
clamonacc changes:
- Renamed FANOTIFY macro to HAVE_SYS_FANOTIFY_H to better match other
similar macros.
- Added a new clamav-clamonacc.service systemd unit file, based on
the work of ChadDevOps & Aaron Brighton.
- Added missing clamonacc man page.
Updates to clamdscan man page, add missing options.
Remove vestigial CL_NOLIBCLAMAV definitions (all apps now use
libclamav).
Rename Windows mspack.dll to libmspack.dll so all ClamAV-built
libraries have the lib-prefix with Visual Studio as with CMake.
Changes cli_checkfp_virus to a recursive function which checks all
parent fmaps in the context for false positives
Simplifies params needed for cli_checkfp_virus to use the current digest
and fmap length that resides within the fmap struct itself
Looking through the list of issues, I spotted some easy ones and submitted
some fixes:
- 225229 - In cli_rarload: Leak of memory or pointers to system resources.
If finding the necessary libunrar functions fails (should be rare),we now
dlclose libunrar.
225224 - In main (freshclam.c): A copied piece of code is inconsistent with
the original (CWE-398). A minor copy-paste error was present, and optOutList
could be cleaned up in one of the failure edge cases.
225228 - In decodecdb: Out-of-bounds access to a buffer (CWE-119). Off by one
error when tokenizing certain CDB sig fields for printing with sigtool. Ex:
$ cat test.cdb
a:CL_TYPE_7Z:1-2-3:/.*/:1-2-3:1-2-3:0:1-2-3::
$ cat test.cdb | ../installed/bin/sigtool --decode
VIRUS NAME: a
CONTAINER TYPE: CL_TYPE_7Z
CONTAINER SIZE: WITHIN RANGE 1 to 2
FILENAME REGEX: /.*/
COMPRESSED FILESIZE: WITHIN RANGE 1 to 2
UNCOMPRESSED FILESIZE: WITHIN RANGE 1 to 2
ENCRYPTION: NO
FILE POSITION: =================================================================
==17245==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7fffe3136d10 at pc 0x7f0f31c3f414 bp 0x7fffe3136c70 sp 0x7fffe3136c60
WRITE of size 8 at 0x7fffe3136d10 thread T0
#0 0x7f0f31c3f413 in cli_strtokenize ../../libclamav/str.c:524
#1 0x559e9797dc91 in decodecdb ../../sigtool/sigtool.c:2929
#2 0x559e9797ea66 in decodesig ../../sigtool/sigtool.c:3058
#3 0x559e9797f31e in decodesigs ../../sigtool/sigtool.c:3162
#4 0x559e97981fbc in main ../../sigtool/sigtool.c:3638
#5 0x7f0f3100fb96 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21b96)
#6 0x559e9795a1d9 in _start (/home/zelda/workspace/clamav-devel/installed/bin/sigtool+0x381d9)
Address 0x7fffe3136d10 is located in stack of thread T0 at offset 48 in frame
#0 0x559e9797d113 in decodecdb ../../sigtool/sigtool.c:2840
This frame has 1 object(s):
[32, 48) 'range' <== Memory access at offset 48 overflows this variable
HINT: this may be a false positive if your program uses some custom stack unwind mechanism or swapcontext
(longjmp and C++ exceptions *are* supported)
SUMMARY: AddressSanitizer: stack-buffer-overflow ../../libclamav/str.c:524 in cli_strtokenize
- 225223 - In cli_egg_deflate_decompress: Reads an uninitialized pointer or
its target (CWE-457). Certain fail cases would call inflateEnd on an
uninitialized stream. Now it’s only called after initialization occurs.
- 225220 - In buildcld: Use of an uninitialized variable (CWE-457). Certain
fail cases would result in oldDir being used before initialization. It now
gets zeroed before the first fail case.
- 225219 - In cli_egg_open: Leak of memory or pointers to system resources
(CWE-404). If certain realloc’s failed, several structures would not be cleaned up
- 225218 - In cli_scanhwpml: Code block is unreachable because of the syntactic
structure of the code (CWE-561). With certain macros set, there could be two
consecutive return statements.
Some detections, like phishing, are considered heuristic alerts because
they match based on behavior more than on content. A subset of these
are considered "potentially unwanted" (low-severity). These
low-severity alerts include:
- phishing
- PDFs with obfuscated object names
- bytecode signature alerts that start with "BC.Heuristics"
The concept is that unless you enable "heuristic precedence" (a method
of lowing the threshold to immediateley alert on low-severity
detections), the scan should continue after a match in case a higher
severity match is found. Only at the end will it print the low-severity
match if nothing else was found.
The current implementation is buggy though. Scanning of archives does
not correctly bail out for the entire archive if one email contains a
phishing link. Instead, it sets the "heuristic found" flag then and
alerts for every subsequent file in the archive because it doesn't know
if the heuristic was found in an embedded file or the target file.
Because it's just a heuristic and the status is "clean", it keeps
scanning.
This patch corrects the behavior by checking if a low-severity alerts
were found at the end of scanning the target file, instead of at the end
of each embedded file.
Additionally, this patch fixes an in issue with phishing alerts wherein
heuristic precedence mode did not cause a scan to stop after the first
alert.
The above changes required restructuring to create an fmap inside of
cl_scandesc_callback() so that scan_common() could be modified to
require an fmap and set up so that the current *ctx->fmap pointer is
never NULL when scan_common() evaluates match results.
Also fixed a couple minor bugs in the phishing unit tests and cleaned up
the test code for improved legitibility and type safety.
This commit improves the layout of the tmp file output and the JSON
metadata output when using the --leave-temps and --gen-json options.
For all scans, each scan target will get a unique tmp sub-directory. If
using --leave-temps, that subdir will include the basename of the
original file to make it easier to identify. Additionally, when using
--leave-temps option, all extracted objects will have their
subdirectories extracted in recursive subdirectories including filename
prefixes where available. When not using the --leave-temps option, the
layout of the tmp sub-directory will remain flat, so as to alleviate the
possibility of exceeding PATH_MAX.
The JSON metadata generated by the --gen-json option is now generated
for all file types, not just a select few. The format is also
pretty-printed for readability and now includes filenames and file paths
when available.
Also:
- Added missing ALLMATCH check when determining if bytecode hooks should
be run.
- Added cl_engine_get_str API to windows libclamav symbol export file.
Instead of checking the Authenticode header as an FP prevention
mechanism, we now check it in the beginning if it exists. Also,
we can now do actual blacklisting with .crb rules (previously, a
blacklist rule just let you override a whitelist rule).
Updated libclamav documentation detailing new scan options structure.
Renamed references to 'algorithmic' detection to 'heuristic' detection. Renaming references to 'properties' to 'collect metadata'.
Renamed references to 'scan all' to 'scan all match'.
Renamed a couple of 'Hueristic.*' signature names as 'Heuristics.*' signatures (plural) to match majority of other heuristics.
mko-x