Description
Heap-based buffer overflow in the SPF_dns_resolv_lookup function in Spf_dns_resolv.c in libspf2 before 1.2.8 allows remote attackers to execute arbitrary code via a long DNS TXT record with a modified length field.
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 | libspf2 | 1.2.9-1 | — |
| Debian 13 | libspf2 | 1.2.9-1 | — |
| Debian 12 | libspf2 | 1.2.9-1 | — |
| Debian 5.0 | libspf2 | 1.2.5.dfsg-5+lenny1 | DTSA-172-1 |
| Debian 4.0 | libspf2 | 1.2.5-4+etch1 | DSA-1659-1 |
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
- LibSPF2 < 1.2.8 - DNS TXT Record Parsing Bug Heap Overflow (PoC) EDB-6805 · dos · Oct 22, 2008 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 2
- DSA-1659-1 libspf2 - potential remote code execution Debian Security (DSA / DLA) · Mar 9, 2026
- DTSA-172-1 libspf2 - buffer overflow Debian Security (DSA / DLA) · Mar 9, 2026
References
- 32720 third-party-advisory
- 6805 exploit
- 32396 third-party-advisory
- 31881 vdb-entry
- 4487 third-party-advisory
- libspf2-dnstxtrecord-bo(46055) vdb-entry
- https://answers.launchpad.net/ubuntu/gutsy/+source/libspf2/1.2.5.dfsg-4ubuntu0.7.10.1
- http://up2date.astaro.com/2008/11/up2date_7305_released.html
- http://bugs.gentoo.org/show_bug.cgi?format=multiple&id=242254
- DSA-1659 vendor-advisory
- ADV-2008-2896 vdb-entry
- https://bugs.launchpad.net/ubuntu/feisty/+source/libspf2/+bug/271025
- http://www.doxpara.com/?page_id=1256
- http://www.doxpara.com/?p=1263
- GLSA-200810-03 vendor-advisory
- VU#183657 third-party-advisory
- 32496 third-party-advisory
- 32450 third-party-advisory