# CVE-2021-22924: Other in https://github.com/curl/curl

> libcurl may reuse connections with incorrect TLS settings due to flawed path comparison, potentially bypassing certificate verification.

- **Severity:** Low 3.7 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 5 Aug 2021
- **Updated:** 14 Oct 2026
- **Also known as:** ALPINE-CVE-2021-22924, AZL-6367, CLEANSTART-2026-JE81585, CLSA-2021-1632262236, CLSA-2021-1634922534, CLSA-2021-1635459168, CURL-CVE-2021-22924, DEBIAN-CVE-2021-22924, GHSA-qhhj-q26m-mrw8, JLSEC-2025-28, OESA-2021-1300, UBUNTU-CVE-2021-22924

## What is CVE-2021-22924?

CVE-2021-22924 is a low-severity vulnerability in Debian Debian Linux, published on 5 Aug 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

libcurl keeps previously used connections in a connection pool for subsequenttransfers to reuse, if one of them matches the setup.Due to errors in the logic, the config matching function did not take 'issuercert' into account and it compared the involved paths *case insensitively*,which could lead to libcurl reusing wrong connections.File paths are, or can be, case sensitive on many systems but not all, and caneven vary depending on used file systems.The comparison also didn't include the 'issuer cert' which a transfer can setto qualify how to verify the server certificate.

Weakness: CWE-706 (Use of Incorrectly-Resolved Name or Reference), CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2021-22924?

It affects 33 products.


Products: Debian Debian Linux, Fedoraproject Fedora, Haxx Libcurl, Netapp Cloud Backup, Netapp Clustered Data Ontap, Netapp Solidfire \& Hci Management Node, Netapp Solidfire Baseboard Management Controller Firmware, Oracle Mysql Server, Oracle Peoplesoft Enterprise Peopletools, Siemens Logo\! Cmr2020 Firmware, Siemens Logo\! Cmr2040 Firmware, Siemens Ruggedcomrm 1224 Lte Firmware, Siemens Scalance M804pb Firmware, Siemens Scalance M812-1 Firmware, Siemens Scalance M816-1 Firmware, Siemens Scalance M826-2 Firmware, Siemens Scalance M874-2 Firmware, Siemens Scalance M874-3 Firmware, Siemens Scalance M876-3 Firmware, Siemens Scalance M876-4 Firmware and 13 more.

## How do I fix CVE-2021-22924?

Upgrade to a fixed version.

## Is CVE-2021-22924 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-22924 exists.

Public exploit code:

- https://github.com/Trinadh465/external_curl_AOSP10_r33_CVE-2021-22924 (github_poc): https://github.com/Trinadh465/external_curl_AOSP10_r33_CVE-2021-22924

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-22924 and fix it if it is affected.

What it is: CVE-2021-22924 is a low-severity vulnerability in Debian Debian Linux, published on 5 Aug 2021. 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-2021-22924 exists.

Affected product: Debian Debian Linux. 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-2021-22924/ (Markdown: https://insights.sbomify.com/CVE-2021-22924/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-22924
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-22924
- OSV: https://osv.dev/vulnerability/CVE-2021-22924

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-22924/
Summaries are generated and may contain mistakes; the official description above is the record.