# CVE-2012-2663: Security feature bypass in n/a

> Remote attackers can bypass firewall restrictions by sending crafted TCP SYN+FIN packets that evade SYN rule matching in iptables.

- **Severity:** High 7.5 (`AV:N/AC:L/Au:N/C:P/I:P/A:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Feb 2014
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2012-2663, ECHO-ee0d-a49e-a573, GHSA-g725-p8m6-82j4, UBUNTU-CVE-2012-2663

## What is CVE-2012-2663?

CVE-2012-2663 is a high-severity vulnerability in n/a, published on 15 Feb 2014. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

## Which versions are affected by CVE-2012-2663?

It affects 1 product.


Products: Netfilter Iptables.

## How do I fix CVE-2012-2663?

Apply the vendor's patch.

## Is CVE-2012-2663 being exploited?

There is no known exploitation of CVE-2012-2663 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2001-1388](https://insights.sbomify.com/CVE-2001-1388/): Misconfiguration in n/a (medium 5.0)
- [CVE-2019-11360](https://insights.sbomify.com/CVE-2019-11360/): Memory corruption in n/a (medium 4.2)
- [CVE-2001-1387](https://insights.sbomify.com/CVE-2001-1387/): Information disclosure in n/a (low 2.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2012-2663 and fix it if it is affected.

What it is: CVE-2012-2663 is a high-severity vulnerability in n/a, published on 15 Feb 2014. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2012-2663 in the wild and no public exploit code.

Affected product: n/a. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2012-2663/ (Markdown: https://insights.sbomify.com/CVE-2012-2663/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2012-2663
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2012-2663
- OSV: https://osv.dev/vulnerability/CVE-2012-2663

---
From sbomify Insights: https://insights.sbomify.com/CVE-2012-2663/
Summaries are generated and may contain mistakes; the official description above is the record.