--- title: "CVE-2012-2663\n | Ubuntu" description: Ubuntu is an open source software operating system that runs from the desktop, to the cloud, to all your internet connected things. url: https://ubuntu.com/security/CVE-2012-2663?format=md keywords: index, follow --- # CVE-2012-2663 Publication date 15 February 2014 Last updated 4 August 2025 --- Ubuntu priority **Low** [Why this priority?](https://ubuntu.com/security/cves/about#priority ) Toggle side navigation ## Description extensions/libxt\_tcp.c in iptables through 1.4.21 does not match TCP SYN+FIN packets in --syn rules, which might allow remote attackers to bypass intended firewall restrictions via crafted packets. NOTE: the CVE-2012-6638 fix makes this issue less relevant. [Read the notes from the security team](https://ubuntu.com/security/CVE-2012-2663?format=md#notes) ## Status Show unmaintained releases | Package | Ubuntu Release | Status | | --- | --- | --- | | iptables | 20.04 LTS focal | Ignored | | 19.10 eoan | Ignored end of life | | 19.04 disco | Ignored end of life | | 18.10 cosmic | Ignored end of life | | 18.04 LTS bionic | Ignored | | 17.10 artful | Ignored end of life | | 17.04 zesty | Ignored end of life | | 16.10 yakkety | Ignored end of life | | 16.04 LTS xenial | Ignored | | 15.10 wily | Ignored end of life | | 15.04 vivid | Ignored end of life | | 14.10 utopic | Ignored end of life | | 14.04 LTS trusty | Ignored end of standard support | | 13.10 saucy | Ignored end of life | | 13.04 raring | Ignored end of life | | 12.10 quantal | Ignored end of life | | 12.04 LTS precise | Ignored end of life | | 11.10 oneiric | Ignored end of life | | 11.04 natty | Ignored end of life | | 10.04 LTS lucid | Ignored end of life | | 8.04 LTS hardy | Ignored end of life | --- * [How can I get the fixes?](https://ubuntu.com/security/cves/about#security) * [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses) ## Notes --- ### [sbeattie](https://launchpad.net/~sbeattie) This is an iptables userspace issue. A kernel CVE was also assigned as CVE-2012-6638, which has been addressed in Ubuntu kernels. --- ### [mdeslaur](https://launchpad.net/~mdeslaur) There is no available fix for this issue for iptables, and changing this would result in an unexpected change in behaviour. We will not be fixing this in Ubuntu stable releases, marking as ignored. ## References * [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2012-2663) * [NVD](https://nvd.nist.gov/vuln/detail/CVE-2012-2663) * [Launchpad](https://launchpad.net/bugs/cve/CVE-2012-2663) * [Debian](https://security-tracker.debian.org/tracker/CVE-2012-2663) ### Other references * * *