PatchSiren

PatchSiren cyber security CVE debrief

CVE-2017-20240 ARODLAND CVE debrief

CVE-2017-20240 is a medium-severity vulnerability in Crypt::PBKDF2 versions before 0.261630 for Perl. The vulnerability allows timing attacks due to the use of Perl's built-in eq comparison, which can lead to discrepancies in timing that could be used to guess the underlying derived-key. The CVSS score for this vulnerability is 5.9, indicating a medium severity level.

Vendor
ARODLAND
Product
Crypt::PBKDF2
CVSS
MEDIUM 5.9
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-12
Original CVE updated
2026-06-12
Advisory published
2026-06-12
Advisory updated
2026-06-12

Who should care

Developers and administrators using Crypt::PBKDF2 versions before 0.261630 for Perl should be aware of this vulnerability and take steps to mitigate it.

Technical summary

The vulnerability is caused by the use of Perl's built-in eq comparison in Crypt::PBKDF2 versions before 0.261630. This allows an attacker to launch a timing attack, which can be used to guess the underlying derived-key.

Defensive priority

Medium

Recommended defensive actions

  • Update Crypt::PBKDF2 to version 0.261630 or later.
  • Use a secure comparison function, such as a constant-time comparison function.

Evidence notes

The vulnerability was reported by an unknown vendor and has a low confidence level.

Sources and references

Verified primary and authoritative sources

  • CVE-2017-20240 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2017-20240

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2017-20240 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2017-20240

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source reference

    Unverified legacy reference

    URL: https://github.com/arodland/Crypt-PBKDF2/pull/6

    9b29abf9-4ab0-4765-b253-1875cd9b441e

  • Source reference

    Unverified legacy reference

    URL: https://metacpan.org/release/ARODLAND/Crypt-PBKDF2-0.161520/source/lib/Crypt/PBKDF2.pm

    9b29abf9-4ab0-4765-b253-1875cd9b441e

  • Source reference

    Unverified legacy reference

    URL: https://metacpan.org/release/ARODLAND/Crypt-PBKDF2-0.261630/changes

    9b29abf9-4ab0-4765-b253-1875cd9b441e

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.