Auth bypass in Ntp

CVE-2009-0021

NTP 4.2.4 before 4.2.4p5 and 4.2.5 before 4.2.5p150 does not properly check the return value from the OpenSSL EVP_VerifyFinal function, which allows remote attackers to bypass validation of the certificate chain via a malformed SSL/TLS signature for DSA and ECDSA keys, a similar vulnerability to CVE-2008-5077.

Vulnerability class: Broken Authentication

EPSS: 0.031 (86.4th percentile) — read the EPSS interpretation.

Affected products

  • Ntp — versions 4.2.0, 4.2.2, 4.2.4p1
  • N/a — versions n/a

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2009-0021?
CVE-2009-0021 is a vulnerability in Ntp, classified under Improper Authentication. Published 2009-01-07.
Is CVE-2009-0021 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.