CVE-2012-1458
MediumThe Microsoft CHM file parser in ClamAV 0.96.4 and Sophos Anti-Virus 4.61.0 allows remote attackers to bypass malware detection via a crafted reset interval in the LZXC header of a CHM file.
Published Mar 21, 2012 · Updated Aug 4, 2026 · Also known as DEBIAN-CVE-2012-1458
Key Facts
Patch immediately- CVE-2012-1458 is a medium-severity vulnerability (CVSS 4.3 v2) affecting Clamav, Sophos Anti-Virus.
- It is not listed in any known-exploited vulnerabilities catalog. No public exploit code is known.
- EPSS estimates a 74% probability of exploitation in the next 30 days.
- Fixed versions are available, including Clamav 0.97.5+dfsg-1, Clamav 0.99.2-4.1.
- Brandefense priority: patch immediately, because it is very likely to be exploited soon.
CVSS v2
4.3
AV:N/AC:M/Au:N/C:N/I:P/A:N
EPSS (30-day exploit likelihood)
74%
Higher than 99.4% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
None known
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Description
The Microsoft CHM file parser in ClamAV 0.96.4 and Sophos Anti-Virus 4.61.0 allows remote attackers to bypass malware detection via a crafted reset interval in the LZXC header of a CHM file. NOTE: this may later be SPLIT into multiple CVEs if additional information is published showing that the error occurred independently in different CHM parser implementations.
Affected Products
14 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| ClamavClamav | 0.96.4 | 0.97.5+dfsg-1 |
| Sophos Anti-VirusSophos | 4.61.0 | n/a |
Patched Releases
Clamav
0.97.5+dfsg-1, 0.99.2-4.1
Timeline
Publicly disclosed
Mar 21, 2012
Last updated
Aug 4, 2026
Weakness Type
- CWE-264
References
- advisoryhttps://security-tracker.debian.org/tracker/CVE-2012-1458
- otheropenSUSE-SU-2012:0833
- other80473
- other80474
- othermultiple-av-chm-header-evasion(74301)
FAQ
Common Questions.
The Microsoft CHM file parser in ClamAV 0.96.4 and Sophos Anti-Virus 4.61.0 allows remote attackers to bypass malware detection via a crafted reset interval in the LZXC header of a CHM file.
Affected: Clamav versions 0.96.4; Sophos Anti-Virus versions 4.61.0. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
Fixed versions are available, including Clamav 0.97.5+dfsg-1, Clamav 0.99.2-4.1.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.
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