# CVE-2022-21723: Out-of-bounds read in multipart parsing in PJSIP

> Attackers can trigger out-of-bounds reads in PJSIP by sending malformed SIP multipart messages, potentially causing crashes or data leaks.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 27 Jan 2022
- **Updated:** 4 Nov 2025
- **Also known as:** ALPINE-CVE-2022-21723, DEBIAN-CVE-2022-21723, GHSA-7fw8-54cv-r7pm, UBUNTU-CVE-2022-21723

## What is CVE-2022-21723?

CVE-2022-21723 is a critical memory corruption vulnerability in Debian Debian Linux, published on 27 Jan 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

PJSIP is a free and open source multimedia communication library written in C language implementing standard based protocols such as SIP, SDP, RTP, STUN, TURN, and ICE. In versions 2.11.1 and prior, parsing an incoming SIP message that contains a malformed multipart can potentially cause out-of-bound read access. This issue affects all PJSIP users that accept SIP multipart. The patch is available as commit in the `master` branch. There are no known workarounds.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2022-21723?

It affects 4 products.


Products: Asterisk Certified Asterisk, Debian Debian Linux, Sangoma Asterisk, Teluu Pjsip.

## How do I fix CVE-2022-21723?

Apply the vendor's patch.

## Is CVE-2022-21723 being exploited?

There is no known exploitation of CVE-2022-21723 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2022-23608](https://insights.sbomify.com/CVE-2022-23608/): Use after free in PJSIP (high 8.1)
- [CVE-2017-9358](https://insights.sbomify.com/CVE-2017-9358/): Denial of service in n/a (high 7.5)
- [CVE-2021-37706](https://insights.sbomify.com/CVE-2021-37706/): Potential integer underflow upon receiving STUN message in PJSIP (high 7.3)
- [CVE-2021-46837](https://insights.sbomify.com/CVE-2021-46837/): Null dereference in n/a (medium 6.5)
- [CVE-2020-28242](https://insights.sbomify.com/CVE-2020-28242/): Denial of service in n/a (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-21723 and fix it if it is affected.

What it is: CVE-2022-21723 is a critical memory corruption vulnerability in Debian Debian Linux, published on 27 Jan 2022. 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-2022-21723 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-2022-21723/ (Markdown: https://insights.sbomify.com/CVE-2022-21723/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-21723
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-21723
- OSV: https://osv.dev/vulnerability/CVE-2022-21723

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-21723/
Summaries are generated and may contain mistakes; the official description above is the record.