# CVE-2020-27507: Memory corruption in n/a

> A buffer overflow in Kamailio SIP server allows remote attackers to crash the service or potentially execute arbitrary code via crafted INVITE requests.

- **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:** 15 Mar 2023
- **Updated:** 27 Feb 2025
- **Also known as:** DEBIAN-CVE-2020-27507, DLA-3438-1, GHSA-q52j-c5xj-88qf, UBUNTU-CVE-2020-27507

## What is CVE-2020-27507?

CVE-2020-27507 is a critical memory corruption vulnerability in n/a, published on 15 Mar 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Kamailio SIP before 5.5.0 server mishandles INVITE requests with duplicated fields and overlength tag, leading to a buffer overflow that crashes the server or possibly have unspecified other impact.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input)

## Which versions are affected by CVE-2020-27507?

It affects 1 product.


Products: Kamailio Kamailio.

## How do I fix CVE-2020-27507?

Upgrade to a fixed version.

## Is CVE-2020-27507 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-27507 exists.

## Other vulnerabilities in n/a

- [CVE-2013-7426](https://insights.sbomify.com/CVE-2013-7426/): File upload in n/a (critical 9.8)
- [CVE-2015-1590](https://insights.sbomify.com/CVE-2015-1590/): Path traversal in n/a (high 7.8)
- [CVE-2015-1591](https://insights.sbomify.com/CVE-2015-1591/): Privilege escalation in n/a (high 7.8)
- [CVE-2026-52022](https://insights.sbomify.com/CVE-2026-52022/): Denial of service in n/a (high 7.5)
- [CVE-2026-52023](https://insights.sbomify.com/CVE-2026-52023/): Denial of service in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-27507 and fix it if it is affected.

What it is: CVE-2020-27507 is a critical memory corruption vulnerability in n/a, published on 15 Mar 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-27507 exists.

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-2020-27507/ (Markdown: https://insights.sbomify.com/CVE-2020-27507/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-27507
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-27507
- OSV: https://osv.dev/vulnerability/CVE-2020-27507

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-27507/
Summaries are generated and may contain mistakes; the official description above is the record.