CVE-2008-2327: Buffer Overflow
Drew Yao of Apple Product Security reported a flaw in the LZW decoder used by libtiff to handle LZW-encoded images. Translation table used by decoding algorithm is not properly re-initialized after "code clear" code is read from the stream being decoded. When reading that code, decoder should discard previous translation table and start filling it again.
Later during the processing, no longer valid table entries may be indexed by the input stream, causing libtiff to follow no longer valid pointer. This can result in crash, memory corruption and possibly allow code execution.
References: http://www.remotesensing.org/libtiff/ http://en.wikipedia.org/wiki/Lzw
Acknowledgements:
Red Hat would like to thank Drew Yao of the Apple Product Security team for reporting this issue.
Other sources
Multiple buffer underflows in the (1) LZWDecode, (2) LZWDecodeCompat, and (3) LZWDecodeVector functions in tiflzw.c in the LZW decoder in LibTIFF 3.8.2 and earlier allow context-dependent attackers to execute arbitrary code via a crafted TIFF file, related to improper handling of the CODECLEAR code.
— MITRE
Affected Software
Remediation
Patch Available
Event History
Frequently Asked Questions
What is the severity of CVE-2008-2327?
CVE-2008-2327 is considered to have a moderate severity level due to its potential impact on the integrity of LZW-encoded images.
How do I fix CVE-2008-2327?
To fix CVE-2008-2327, upgrade libtiff to version 3.8.3 or later.
Which versions of libtiff are affected by CVE-2008-2327?
CVE-2008-2327 affects libtiff versions up to and including 3.8.2, as well as specific earlier versions including 3.4, 3.5.1 to 3.8.1.
What is the impact of CVE-2008-2327 on systems using libtiff?
The impact of CVE-2008-2327 can lead to application crashes or execution of arbitrary code when handling LZW-encoded images.
Is there a workaround for CVE-2008-2327 if I cannot update libtiff?
There is no known workaround for CVE-2008-2327, so updating to a patched version is strongly recommended.