# CVE-2022-42705: Use after free in n/a

> A remote authenticated attacker can crash the Asterisk PBX server by triggering a use-after-free condition during concurrent subscription activities.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/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:** 5 Dec 2022
- **Updated:** 24 Apr 2025
- **Also known as:** ALPINE-CVE-2022-42705, DEBIAN-CVE-2022-42705, GHSA-89gw-96wv-f4r4, UBUNTU-CVE-2022-42705

## What is CVE-2022-42705?

CVE-2022-42705 is a medium-severity use after free vulnerability in n/a, published on 5 Dec 2022. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A use-after-free in res_pjsip_pubsub.c in Sangoma Asterisk 16.28, 18.14, 19.6, and certified/18.9-cert2 may allow a remote authenticated attacker to crash Asterisk (denial of service) by performing activity on a subscription via a reliable transport at the same time that Asterisk is also performing activity on that subscription.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2022-42705?

It affects 2 products.


Products: Sangoma Asterisk, Sangoma Certified Asterisk.

## How do I fix CVE-2022-42705?

Apply the vendor's patch.

## Is CVE-2022-42705 being exploited?

There is no known exploitation of CVE-2022-42705 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2024-57520](https://insights.sbomify.com/CVE-2024-57520/): Path traversal in n/a (critical 9.8)
- [CVE-2025-47779](https://insights.sbomify.com/CVE-2025-47779/): Using malformed From header can forge identity with ";" or NULL in name portion (high 7.7)
- [CVE-2025-57767](https://insights.sbomify.com/CVE-2025-57767/): Asterisk can crash from a specifically malformed Authorization header in an incoming SIP request (high 7.5)
- [CVE-2022-37325](https://insights.sbomify.com/CVE-2022-37325/): Memory corruption in n/a (high 7.5)
- [CVE-2025-1131](https://insights.sbomify.com/CVE-2025-1131/): Asterisk Unsafe Shell Sourcing in safe_asterisk Leads to Local Privilege Escalation (high 7.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-42705 and fix it if it is affected.

What it is: CVE-2022-42705 is a medium-severity use after free vulnerability in n/a, published on 5 Dec 2022. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2022-42705 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-2022-42705/ (Markdown: https://insights.sbomify.com/CVE-2022-42705/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-42705
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-42705
- OSV: https://osv.dev/vulnerability/CVE-2022-42705

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-42705/
Summaries are generated and may contain mistakes; the official description above is the record.