A memory corruption vulnerability in CHMlib could lead to the remote execution of arbitrary code.
| Package | Arch | Vulnerable | Unaffected |
|---|---|---|---|
| dev-libs/chmlib | * | < 0.39 | >= 0.39 |
CHMlib is a library for the MS CHM (Compressed HTML) file format plus extracting and HTTP server utils.
When certain CHM files that contain tables and objects stored in pages are parsed by CHMlib, an unsanitized value is passed to the alloca() function resulting in a shift of the stack pointer to arbitrary memory locations.
An attacker could entice a user to open a specially crafted CHM file, resulting in the execution of arbitrary code with the permissions of the user viewing the file.
There is no known workaround at this time.
All CHMlib users should upgrade to the latest version:
# emerge --sync # emerge --ask --oneshot --verbose ">=dev-libs/chmlib-0.39"
chmlib and KchmViewer contain a buffer overflow vulnerability which may lead to the execution of arbitrary code.
| Package | Arch | Vulnerable | Unaffected |
|---|---|---|---|
| app-text/kchmviewer | * | < 1.1 | >= 1.1 |
| dev-libs/chmlib | * | < 0.37.4 | >= 0.37.4 |
chmlib is a library for dealing with Microsoft ITSS and CHM format files. KchmViewer is a CHM viewer that includes its own copy of the chmlib library.
Sven Tantau reported about a buffer overflow vulnerability in chmlib. The function "_chm_decompress_block()" does not properly perform boundary checking, resulting in a stack-based buffer overflow.
By convincing a user to open a specially crafted ITSS or CHM file, using KchmViewer or a program makes use of chmlib, a remote attacker could execute arbitrary code with the privileges of the user running the software.
There is no known workaround at this time.
All chmlib users should upgrade to the latest version:
# emerge --sync # emerge --ask --oneshot --verbose ">=dev-libs/chmlib-0.37.4"
All KchmViewer users should upgrade to the latest version:
# emerge --sync # emerge --ask --oneshot --verbose ">=app-text/kchmviewer-1.1"