Description
Heap-based buffer overflow in the pefromupx function in libclamav/upx.c in Clam AntiVirus (ClamAV) 0.81 through 0.88.3 allows remote attackers to execute arbitrary code via a crafted UPX packed file containing sections with large rsize values.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | clamav | 0.88.4-1 | — |
| Debian 13 | clamav | 0.88.4-1 | — |
| Debian 12 | clamav | 0.88.4-1 | — |
| Debian 3.1 | clamav | 0.84-2.sarge.10 | DSA-1153 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
Exploit-DB 1
- Clam Anti-Virus ClamAV 0.88.x - UPX Compressed PE File Heap Buffer Overflow EDB-28348 · dos · Aug 7, 2006 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 1
- DSA-1153 clamav - buffer overflow Debian Security (DSA / DLA) · Mar 9, 2026
References
- ADV-2006-3175 vdb-entry
- 20060809 [Overflow.pl] Clam AntiVirus Win32-UPX Heap Overflow mailing-list
- 21562 third-party-advisory
- SUSE-SA:2006:046 vendor-advisory
- 21368 third-party-advisory
- 21433 third-party-advisory
- GLSA-200608-13 vendor-advisory
- 21497 third-party-advisory
- http://kolab.org/security/kolab-vendor-notice-10.txt
- DSA-1153 vendor-advisory
- 21443 third-party-advisory
- MDKSA-2006:138 vendor-advisory
- 19381 vdb-entry
- 1016645 vdb-entry
- http://www.overflow.pl/adv/clamav_upx_heap.txt
- http://www.clamav.net/security/0.88.4.html
- clamav-pefromupx-bo(28286) vdb-entry
- 2006-0046 vendor-advisory
- 21457 third-party-advisory
- 21374 third-party-advisory
- ADV-2006-3275 vdb-entry