chmlib, KchmViewer: Stack-based buffer overflow

chmlib, KchmViewer: Stack-based buffer overflow chmlib and KchmViewer contain a buffer overflow vulnerability which may lead to the execution of arbitrary code. chmlib kchmviewer November 28, 2005 May 28, 2009: 03 110557 remote 0.37.4 0.37.4 1.1 1.1

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"

CVE-2005-3318 koon adir adir