CVE-2017-20240 Crypt::PBKDF2 versions before 0.261630 for Perl are vulnerable to timing attacks
An attacker can exploit timing discrepancies in key comparison to guess the derived key, compromising password security.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2017-20240?
CVE-2017-20240 is a medium-severity vulnerability in ARODLAND Crypt::PBKDF2, published on 12 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-208
Which versions are affected by CVE-2017-20240?
How do I fix CVE-2017-20240?
Upgrade to a fixed version.
Is CVE-2017-20240 being exploited?
There is no known exploitation of CVE-2017-20240 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2017-20240, GHSA-m538-6wp4-7h22, UBUNTU-CVE-2017-20240.