# CVE-2021-22925: Information disclosure in https://github.com/curl/curl

> A flaw in curl's telnet option parser allows attackers to read uninitialized stack data, potentially revealing sensitive internal information.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/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-2021-22925, AZL-6363, CLEANSTART-2026-AP31271, CLSA-2021-1632261944, CLSA-2021-1634922501, CLSA-2021-1634922517, CLSA-2021-1635459174, CURL-CVE-2021-22925, GHSA-rjqf-6h27-xqfp, JLSEC-2026-1337, UBUNTU-CVE-2021-22925

## What is CVE-2021-22925?

CVE-2021-22925 is a medium-severity vulnerability in Apple Mac Os X, published on 5 Aug 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

curl supports the `-t` command line option, known as `CURLOPT_TELNETOPTIONS`in libcurl. This rarely used option is used to send variable=content pairs toTELNET servers.Due to flaw in the option parser for sending `NEW_ENV` variables, libcurlcould be made to pass on uninitialized data from a stack based buffer to theserver. Therefore potentially revealing sensitive internal information to theserver using a clear-text network protocol.This could happen because curl did not call and use sscanf() correctly whenparsing the string provided by the application.

Weakness: CWE-908 (Use of Uninitialized Resource), CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2021-22925?

It affects 20 products.


Products: Apple Mac Os X, Apple Macos, Fedoraproject Fedora, Haxx Curl, Netapp Cloud Backup, Netapp Clustered Data Ontap, Netapp H300e Firmware, Netapp H300s Firmware, Netapp H410s Firmware, Netapp H500e Firmware, Netapp H500s Firmware, Netapp H700e Firmware, Netapp H700s Firmware, Netapp Hci Management Node, Netapp Solidfire, Oracle Mysql Server, Oracle Peoplesoft Enterprise Peopletools, Siemens Sinec Infrastructure Network Services, Siemens Sinema Remote Connect Server, Splunk Universal Forwarder.

## How do I fix CVE-2021-22925?

Upgrade to a fixed version.

## Is CVE-2021-22925 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-22925 exists.

## Other vulnerabilities in Apple Mac Os X

- [CVE-2014-7169](https://insights.sbomify.com/CVE-2014-7169/): GNU Bourne-Again Shell (Bash) Arbitrary Code Execution (critical 9.8, exploited in the wild)
- [CVE-2014-6271](https://insights.sbomify.com/CVE-2014-6271/): GNU Bourne-Again Shell (Bash) Arbitrary Code Execution (critical 9.8, exploited in the wild)
- [CVE-2012-1823](https://insights.sbomify.com/CVE-2012-1823/): PHP-CGI Query String Parameter (critical 9.8, exploited in the wild)
- [CVE-2021-30713](https://insights.sbomify.com/CVE-2021-30713/): Apple macOS Unspecified (high 7.8, exploited in the wild)
- [CVE-2019-8526](https://insights.sbomify.com/CVE-2019-8526/): Apple macOS Use-After-Free (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-22925 and fix it if it is affected.

What it is: CVE-2021-22925 is a medium-severity vulnerability in Apple Mac Os X, 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-2021-22925 exists.

Affected product: Apple Mac Os X. 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-2021-22925/ (Markdown: https://insights.sbomify.com/CVE-2021-22925/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-22925
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-22925
- OSV: https://osv.dev/vulnerability/CVE-2021-22925

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-22925/
Summaries are generated and may contain mistakes; the official description above is the record.