# CVE-2013-1121: Denial of service in n/a

> Remote attackers can cause a device reload in Cisco NX-OS by sending crafted AS paths when complex regex is configured for inbound BGP routes.

- **Severity:** Medium 5.4 (`AV:N/AC:H/Au:N/C:N/I:N/A:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 Sep 2013
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-fhpq-rxph-9fx4

## What is CVE-2013-1121?

CVE-2013-1121 is a medium-severity denial of service vulnerability in Cisco Nx-Os, published on 19 Sep 2013. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The regex engine in the BGP implementation in Cisco NX-OS, when a complex regular expression is configured for inbound routes, allows remote attackers to cause a denial of service (device reload) via a crafted AS path set, aka Bug ID CSCuf49554.

Weakness: CWE-399

## Which versions are affected by CVE-2013-1121?

It affects 1 product.


Products: Cisco Nx-Os.

## How do I fix CVE-2013-1121?

No fix has been published for CVE-2013-1121 yet. Limit exposure of the affected software until one is available.

## Is CVE-2013-1121 being exploited?

There is no known exploitation of CVE-2013-1121 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Nx-Os

- [CVE-2024-20399](https://insights.sbomify.com/CVE-2024-20399/): Cisco NX-OS Command Injection (medium 6.0, exploited in the wild)
- [CVE-2021-1361](https://insights.sbomify.com/CVE-2021-1361/): Cisco NX-OS Software Unauthenticated Arbitrary File Actions Vulnerability (critical 9.8)
- [CVE-2018-0301](https://insights.sbomify.com/CVE-2018-0301/): Memory corruption in Cisco NX-OS unknown (critical 9.8)
- [CVE-2016-1453](https://insights.sbomify.com/CVE-2016-1453/): Memory corruption in n/a (critical 9.8)
- [CVE-2016-1341](https://insights.sbomify.com/CVE-2016-1341/): Hardcoded credentials in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2013-1121 and fix it if it is affected.

What it is: CVE-2013-1121 is a medium-severity denial of service vulnerability in Cisco Nx-Os, published on 19 Sep 2013. 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-2013-1121 in the wild and no public exploit code.

Affected product: Cisco Nx-Os. 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-2013-1121/ (Markdown: https://insights.sbomify.com/CVE-2013-1121/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2013-1121
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2013-1121
- OSV: https://osv.dev/vulnerability/CVE-2013-1121

---
From sbomify Insights: https://insights.sbomify.com/CVE-2013-1121/
Summaries are generated and may contain mistakes; the official description above is the record.