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

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.

Published: 2026-06-12 Last update: 2026-06-16 Assigner: 9b29abf9-4ab0-4765-b253-1875cd9b441e Source: 9b29abf9-4ab0-4765-b253-1875cd9b441e
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2017-20240 is rated Low Risk (32.1/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.32%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2017-20240

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.03% 0.32% +0.29%
2 2026-06-13 — 0.03% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2017-20240

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.2 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2017-20240

GitHub Security Advisory for CVE-2017-20240

GHSA-m538-6wp4-7h22 · Severity: medium — Crypt::PBKDF2 versions before 0.261630 for Perl are vulnerable to timing attacks. These versions...

OS Trackers for CVE-2017-20240

vendor priority summary link
debian not yet assigned CVE-2017-20240 not yet assigned priority: Debian including 1 source packages (libcrypt-pbkdf2-perl), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 3, resolved 2. https://security-tracker.debian.org/tracker/CVE-2017-20240
suse medium CVE-2017-20240 severity moderate: SUSE including 1 source package names (perl-Crypt-PBKDF2-0.261630-1.1), 1 product×package rows across 1 product lines (openSUSE Tumbleweed): Fixed 1. https://www.suse.com/security/cve/CVE-2017-20240/
ubuntu medium CVE-2017-20240 medium priority: Ubuntu including 1 source packages (libcrypt-pbkdf2-perl), 7 status rows across 7 suites (bionic, focal, jammy, noble, questing, resolute, upstream): needs-triage 6, released 1. https://ubuntu.com/security/CVE-2017-20240

Affected software / configurations for CVE-2017-20240

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2017-20240

cvelogic Threat Intelligence