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

Classification

CVE ID: CVE-2024-13939

CVSS Base Severity: HIGH

CVSS Base Score: 7.5

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected Products

Vendor: FRACTAL

Product: String::Compare::ConstantTime

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.04% (probability of being exploited)

EPSS Percentile: 11.72% (scored less or equal to compared to others)

EPSS Date: 2025-04-25 (when was this score calculated)

References

https://nvd.nist.gov/vuln/detail/CVE-2024-13939
https://metacpan.org/release/FRACTAL/String-Compare-ConstantTime-0.321/view/lib/String/Compare/ConstantTime.pm#TIMING-SIDE-CHANNEL

Timeline