CVE-2017-20240: Crypt::PBKDF2 versions before 0.261630 for Perl are vulnerable to timing attacks

Severity: medium (CVSS 5.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-12 · updated 2026-06-17
Weakness: CWE-208

Description

Crypt::PBKDF2 versions before 0.261630 for Perl are vulnerable to timing attacks. These versions use Perl's built-in eq comparison. Discrepancies in timing could be used to guess the underlying derived-key.

Affected products

ARODLAND Crypt::PBKDF2: before 0.261630 — fixed in 0.261630

How to fix

Upgrade to a fixed version: ARODLAND Crypt::PBKDF2 0.261630. Check the vendor advisory for mitigations.

References

https://github.com/arodland/Crypt-PBKDF2/pull/6
https://metacpan.org/release/ARODLAND/Crypt-PBKDF2-0.161520/source/lib/Crypt/PBKDF2.pm#L123-148
https://metacpan.org/release/ARODLAND/Crypt-PBKDF2-0.261630/changes
http://www.openwall.com/lists/oss-security/2026/06/12/3

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