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
Published · last modified .
CVSS v2 metric
CVSS v2 base score 5.0 (Medium). Vector: AV:N/AC:L/Au:N/C:P/I:N/A:N. This CVE predates CVSS v3 and has no v3 score from NVD.
EPSS exploit prediction
EPSS: 0.032 (87.7th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 88th percentile — 87.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.032 · newest: 0.032 · change: 0.000
Affected products
- NTP — versions 4.2.0, 4.2.2, 4.2.4p1
Weakness classification (CWE)
Public proof-of-concept exploits
References
- support.apple.com/kb/HT3549
- www.securityfocus.com/archive/1/499827/100/0/threaded (mailing-list)
- www.securitytracker.com/id (vdb-entry)
- lists.ntp.org/pipermail/announce/2009-January/000055.html (mailing-list)
- secunia.com/advisories/34642 (Vendor Advisory, third-party-advisory)
- www.redhat.com/support/errata/RHSA-2009-0046.html (vendor-advisory)
- secunia.com/advisories/35074 (Vendor Advisory, third-party-advisory)
- lists.apple.com/archives/security-announce/2009/May/msg00002.html (vendor-advisory)
- secunia.com/advisories/33558 (Vendor Advisory, third-party-advisory)
- lists.opensuse.org/opensuse-security-announce/2009-03/msg00000.html (vendor-advisory)
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.