Description
nf_conntrack in netfilter in the Linux kernel before 2.6.20.3 does not set nfctinfo during reassembly of fragmented packets, which leaves the default value as IP_CT_ESTABLISHED and might allow remote attackers to bypass certain rulesets using IPv6 fragments.
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 4.0 | linux-2.6 | 2.6.18.dfsg.1-12etch2 | DSA-1289-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 5 | kernel +10 | 2.6.18-8.1.4.el5 | RHSA-2007:0347 |
Advisories 2
- RHSA-2007:0347 Red Hat Security Advisory: kernel security and bug fix update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- DSA-1289-1 linux-2.6 Debian Security (DSA / DLA) · Mar 9, 2026
References
- oval:org.mitre.oval:def:10457 vdb-entry signature
- RHSA-2007:0347 vendor-advisory
- USN-464-1 vendor-advisory
- SUSE-SA:2007:043 vendor-advisory
- http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.20.3
- MDKSA-2007:171 vendor-advisory
- ADV-2007-0944 vdb-entry
- DSA-1289 vendor-advisory
- 25288 third-party-advisory
- 26620 third-party-advisory
- 25228 third-party-advisory
- MDKSA-2007:196 vendor-advisory
- 25961 third-party-advisory
- 24492 third-party-advisory
- 25392 third-party-advisory
- 33028 vdb-entry
- 23976 vdb-entry