# CVE-2024-13939: libstring-compare-constanttime-perl: String::Compare::ConstantTime for Perl through 0.321 is vulnerable to timing attacks that allow an attacker to guess...

CVE-2024-13939 is fixed in libstring-compare-constanttime-perl on 1 platform, first by DEBIAN-CVE-2024-13939, released March 28, 2025. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2024-13939
- Priority: High
- CVSS: 7.5 (high)
- EPSS: 0.0037
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Mar 28, 2025

## Description

String::Compare::ConstantTime for Perl through 0.321 is vulnerable to timing attacks that allow an attacker to guess the length of a secret string.  As stated in the documentation: "If the lengths of the strings are different, because equals returns false right away the size of the secret string may be leaked (but not its contents)."  This is similar to CVE-2020-36829

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | libstring-compare-constanttime-perl Debian 13.5 (trixie) | 0.321-3 | [DEBIAN-CVE-2024-13939](https://patchblox.com/security/data/fix/linux/debian-cve-2024-13939.md) | Mar 28, 2025 |
| Linux | libstring-compare-constanttime-perl Debian 14 | 0.321-3 | [DEBIAN-CVE-2024-13939](https://patchblox.com/security/data/fix/linux/debian-cve-2024-13939.md) | Mar 28, 2025 |

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