# CVE-2023-38703: PJSIP has use-after-free vulnerability in SRTP media transport

> Attackers can trigger a use-after-free in PJSIP SRTP transport, potentially causing application crashes or arbitrary code execution.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:** 6 Oct 2023
- **Updated:** 13 Feb 2025
- **Also known as:** ALPINE-CVE-2023-38703, DEBIAN-CVE-2023-38703, GHSA-f76w-fh7c-pc66, UBUNTU-CVE-2023-38703

## What is CVE-2023-38703?

CVE-2023-38703 is a critical use after free vulnerability in pjsip pjproject, published on 6 Oct 2023. 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 with high level API in C, C++, Java, C#, and Python languages. SRTP is a higher level media transport which is stacked upon a lower level media transport such as UDP and ICE. Currently a higher level transport is not synchronized with its lower level transport that may introduce use-after-free issue. This vulnerability affects applications that have SRTP capability (`PJMEDIA_HAS_SRTP` is set) and use underlying media transport other than UDP. This vulnerability’s impact may range from unexpected application termination to control flow hijack/memory corruption. The patch is available as a commit in the master branch.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2023-38703?

It affects 1 product.


Products: Teluu Pjsip.

## How do I fix CVE-2023-38703?

Apply the vendor's patch.

## Is CVE-2023-38703 being exploited?

There is no known exploitation of CVE-2023-38703 in the wild and no public exploit code.

## Other vulnerabilities in pjsip pjproject

- [CVE-2022-39269](https://insights.sbomify.com/CVE-2022-39269/): Media transport downgrade from the secure version (SRTP) to non-secure (RTP) in pjsip (critical 9.1)
- [CVE-2026-57161](https://insights.sbomify.com/CVE-2026-57161/): PJSIP: Stack overflow handling Service-Route headers in a registration response (high 8.8)
- [CVE-2026-57162](https://insights.sbomify.com/CVE-2026-57162/): PJSIP: Stack overflow parsing SDP a=crypto attributes (high 8.8)
- [CVE-2026-57163](https://insights.sbomify.com/CVE-2026-57163/): PJSIP: Stack overflow parsing a TLS peer certificate's SubjectAltName in GnuTLS backend (high 8.8)
- [CVE-2026-57159](https://insights.sbomify.com/CVE-2026-57159/): PJSIP: SDP parser out-of-bounds write in remote payload-type map maintenance (high 8.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-38703 and fix it if it is affected.

What it is: CVE-2023-38703 is a critical use after free vulnerability in pjsip pjproject, published on 6 Oct 2023. 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-2023-38703 in the wild and no public exploit code.

Affected product: pjsip pjproject. 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-2023-38703/ (Markdown: https://insights.sbomify.com/CVE-2023-38703/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-38703
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-38703
- OSV: https://osv.dev/vulnerability/CVE-2023-38703

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-38703/
Summaries are generated and may contain mistakes; the official description above is the record.