# CVE-2021-22553: Heap Memory exhaustion in Gerrit

> Attackers can exhaust heap memory by creating unexpired sessions via git operations, causing denial of service on Gerrit servers.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 17 Feb 2021
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-f46h-mh94-f4w2

## What is CVE-2021-22553?

CVE-2021-22553 is a medium-severity denial of service vulnerability in Google LLC Gerrit, published on 17 Feb 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Any git operation is passed through Jetty and a session is created. No expiry is set for the session and Jetty does not automatically dispose of the session. Over multiple git actions, this can lead to a heap memory exhaustion for Gerrit servers. We recommend upgrading Gerrit to any of the versions listed above.

Weakness: CWE-772 (Missing Release of Resource after Effective Lifetime), CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2021-22553?

It affects 1 product.


Products: Google Gerrit.

## How do I fix CVE-2021-22553?

No fix has been published for CVE-2021-22553 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-22553 being exploited?

There is no known exploitation of CVE-2021-22553 in the wild and no public exploit code.

## Other vulnerabilities in Google LLC Gerrit

- [CVE-2026-2725](https://insights.sbomify.com/CVE-2026-2725/): Improper Authorization in Gerrit allowing Code Review Bypass via "Submitted Together" (medium 6.0)
- [CVE-2020-8919](https://insights.sbomify.com/CVE-2020-8919/): Information leakage in Gerrit (low 3.5)
- [CVE-2020-8920](https://insights.sbomify.com/CVE-2020-8920/): Overoptimization leads to private information leak in Gerrit (low 3.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-22553 and fix it if it is affected.

What it is: CVE-2021-22553 is a medium-severity denial of service vulnerability in Google LLC Gerrit, published on 17 Feb 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-22553 in the wild and no public exploit code.

Affected product: Google LLC Gerrit. 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-2021-22553/ (Markdown: https://insights.sbomify.com/CVE-2021-22553/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-22553
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-22553
- OSV: https://osv.dev/vulnerability/CVE-2021-22553

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-22553/
Summaries are generated and may contain mistakes; the official description above is the record.