# CVE-2019-13161: Null dereference in n/a

> An attacker can crash the Asterisk PBX by sending a malformed SDP answer during a T.38 re-invite, causing a null pointer dereference.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Jul 2019
- **Updated:** 4 Aug 2024
- **Also known as:** ALPINE-CVE-2019-13161, DEBIAN-CVE-2019-13161, GHSA-5x75-h4p9-mf5p, UBUNTU-CVE-2019-13161

## What is CVE-2019-13161?

CVE-2019-13161 is a medium-severity vulnerability in Debian Debian Linux, published on 12 Jul 2019. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

An issue was discovered in Asterisk Open Source through 13.27.0, 14.x and 15.x through 15.7.2, and 16.x through 16.4.0, and Certified Asterisk through 13.21-cert3. A pointer dereference in chan_sip while handling SDP negotiation allows an attacker to crash Asterisk when handling an SDP answer to an outgoing T.38 re-invite. To exploit this vulnerability an attacker must cause the chan_sip module to send a T.38 re-invite request to them. Upon receipt, the attacker must send an SDP answer containing both a T.38 UDPTL stream and another media stream containing only a codec (which is not permitted according to the chan_sip configuration).

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2019-13161?

It affects 3 products.


Products: Debian Debian Linux, Digium Asterisk, Digium Certified Asterisk.

## How do I fix CVE-2019-13161?

Apply the vendor's patch.

## Is CVE-2019-13161 being exploited?

There is no known exploitation of CVE-2019-13161 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-13161 and fix it if it is affected.

What it is: CVE-2019-13161 is a medium-severity vulnerability in Debian Debian Linux, published on 12 Jul 2019. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2019-13161 in the wild and no public exploit code.

Affected product: Debian Debian Linux. 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-2019-13161/ (Markdown: https://insights.sbomify.com/CVE-2019-13161/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-13161
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-13161
- OSV: https://osv.dev/vulnerability/CVE-2019-13161

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-13161/
Summaries are generated and may contain mistakes; the official description above is the record.