# CVE-2022-36021: Redis string pattern matching can be abused to achieve Denial of Service

> Authenticated users can trigger a denial-of-service attack in Redis by using crafted string matching patterns, causing high CPU usage and service hangs.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/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:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 1 Mar 2023
- **Updated:** 7 Mar 2025
- **Also known as:** AZL-13830, BIT-keydb-2022-36021, BIT-redis-2022-36021, BIT-valkey-2022-36021, DEBIAN-CVE-2022-36021, DLA-3361-1, GHSA-jr7j-rfj5-8xqv, OESA-2023-1184, UBUNTU-CVE-2022-36021

## What is CVE-2022-36021?

CVE-2022-36021 is a medium-severity denial of service vulnerability in redis, published on 1 Mar 2023. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Redis is an in-memory database that persists on disk. Authenticated users can use string matching commands (like `SCAN` or `KEYS`) with a specially crafted pattern to trigger a denial-of-service attack on Redis, causing it to hang and consume 100% CPU time. The problem is fixed in Redis versions 6.0.18, 6.2.11, 7.0.9.

Weakness: CWE-407 (Inefficient Algorithmic Complexity)

## Which versions are affected by CVE-2022-36021?

3 open source packages ship an affected version, including redis, keydb and valkey. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `redis` | Bitnami | All versions | 6.0.18, 6.2.11, 7.0.9 |
| `keydb` | Bitnami | All versions | 6.0.18, 6.2.11, 7.0.9 |
| `valkey` | Bitnami | All versions | 6.0.18, 6.2.11, 7.0.9 |

Products: Redis Redis.

## How do I fix CVE-2022-36021?

Upgrade redis to a fixed version for your release line: 6.0.18, 6.2.11 or 7.0.9.

## Is CVE-2022-36021 being exploited?

There is no known exploitation of CVE-2022-36021 in the wild and no public exploit code.

## Other vulnerabilities in redis

- [CVE-2022-0543](https://insights.sbomify.com/CVE-2022-0543/): Debian-specific Redis Server Lua Sandbox Escape (critical 10.0, exploited in the wild)
- [CVE-2026-23479](https://insights.sbomify.com/CVE-2026-23479/): redis-server use-after-free in unblock client flow may allow remote code execution (high 7.7)
- [CVE-2026-25243](https://insights.sbomify.com/CVE-2026-25243/): redis-server RESTORE invalid memory access may allow remote code execution (high 7.7)
- [CVE-2025-62507](https://insights.sbomify.com/CVE-2025-62507/): Redis: Bug in XACKDEL may lead to stack overflow and potential RCE (high 7.7)
- [CVE-2025-48367](https://insights.sbomify.com/CVE-2025-48367/): Redis DoS Vulnerability due to bad connection error handling (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-36021 and fix it if it is affected.

What it is: CVE-2022-36021 is a medium-severity denial of service vulnerability in redis, published on 1 Mar 2023. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2022-36021 in the wild and no public exploit code.

Affected packages and fixed versions:
- redis (Bitnami): affected all versions; fixed in 6.0.18, 6.2.11, 7.0.9
- keydb (Bitnami): affected all versions; fixed in 6.0.18, 6.2.11, 7.0.9
- valkey (Bitnami): affected all versions; fixed in 6.0.18, 6.2.11, 7.0.9

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-2022-36021/ (Markdown: https://insights.sbomify.com/CVE-2022-36021/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-36021
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-36021
- OSV: https://osv.dev/vulnerability/CVE-2022-36021

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-36021/
Summaries are generated and may contain mistakes; the official description above is the record.