Description
The pop_msg function in qpopper 4.0.x before 4.0.5fc2 does not null terminate a message buffer after a call to Qvsnprintf, which could allow authenticated users to execute arbitrary code via a buffer overflow in a mdef command with a long macro name.
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 3.0 | qpopper | 4.0.4-2.woody.3 | DSA-259 |
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
- Qpopper 4.0.x - Remote Memory Corruption EDB-22342 · remote · Mar 10, 2003 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 1
- DSA-259 qpopper - mail user privilege escalation Debian Security (DSA / DLA) · Mar 9, 2026
References
- GLSA-200303-12 vendor-advisory
- 7058 vdb-entry
- SuSE-SA:2003:018 vendor-advisory
- 20030310 QPopper 4.0.x buffer overflow vulnerability mailing-list
- 20030314 [OpenPKG-SA-2003.018] OpenPKG Security Advisory (qpopper) mailing-list
- DSA-259 vendor-advisory
- qpopper-popmsg-macroname-bo(11516) vdb-entry
- 20030312 Re: QPopper 4.0.x buffer overflow vulnerability mailing-list