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...
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.
Exploit likelihood
What each source reports
NVD Score used
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.
- Record
CVE-2009-0021- CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:P/I:N/A:N - Weakness
- CWE-287
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2009-0021- Updated
- 2026-11-02
EUVDEUVD-2009-0034 No score
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.
- Record
EUVD-2009-0034- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-4q4m-qx69-vcgq No score
NTP 4.2.4 before 4.2.4p5 and 4.2.5 before 4.2.5p150 does not properly check the return value from...
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.
- Record
GHSA-4q4m-qx69-vcgq- Weakness
- CWE-287
- Updated
- 2026-11-02
OSV No score
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.
- Record
CVE-2009-0021- Updated
- 2026-11-02
OSVDEBIAN-CVE-2009-0021 No score
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.
- Record
DEBIAN-CVE-2009-0021- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
ntpDebian:11 |
before 1:4.2.4p4+dfsg-8 | 1:4.2.4p4+dfsg-8 |
ntpDebian:4.0 |
before 1:4.2.2.p4+dfsg-2etch1, plus listed versions 1:4.2.2.p4+dfsg-2 |
1:4.2.2.p4+dfsg-2etch1 |
ntpRed Hat:enterprise_linux:4::as |
before 0:4.2.0.a.20040617-8.el4_7.1 | 0:4.2.0.a.20040617-8.el4_7.1 |
ntp-debuginfoRed Hat:enterprise_linux:4::as |
before 0:4.2.0.a.20040617-8.el4_7.1 | 0:4.2.0.a.20040617-8.el4_7.1 |
ntpRed Hat:enterprise_linux:4::desktop |
before 0:4.2.0.a.20040617-8.el4_7.1 | 0:4.2.0.a.20040617-8.el4_7.1 |
ntp-debuginfoRed Hat:enterprise_linux:4::desktop |
before 0:4.2.0.a.20040617-8.el4_7.1 | 0:4.2.0.a.20040617-8.el4_7.1 |
ntpRed Hat:enterprise_linux:4::es |
before 0:4.2.0.a.20040617-8.el4_7.1 | 0:4.2.0.a.20040617-8.el4_7.1 |
ntp-debuginfoRed Hat:enterprise_linux:4::es |
before 0:4.2.0.a.20040617-8.el4_7.1 | 0:4.2.0.a.20040617-8.el4_7.1 |
ntpRed Hat:enterprise_linux:4::ws |
before 0:4.2.0.a.20040617-8.el4_7.1 | 0:4.2.0.a.20040617-8.el4_7.1 |
ntp-debuginfoRed Hat:enterprise_linux:4::ws |
before 0:4.2.0.a.20040617-8.el4_7.1 | 0:4.2.0.a.20040617-8.el4_7.1 |
Show 4 moreShow less
| Package | Affected | Fixed |
|---|---|---|
ntpRed Hat:enterprise_linux:5::client |
before 0:4.2.2p1-9.el5_3.1 | 0:4.2.2p1-9.el5_3.1 |
ntp-debuginfoRed Hat:enterprise_linux:5::client |
before 0:4.2.2p1-9.el5_3.1 | 0:4.2.2p1-9.el5_3.1 |
ntpRed Hat:enterprise_linux:5::server |
before 0:4.2.2p1-9.el5_3.1 | 0:4.2.2p1-9.el5_3.1 |
ntp-debuginfoRed Hat:enterprise_linux:5::server |
before 0:4.2.2p1-9.el5_3.1 | 0:4.2.2p1-9.el5_3.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2009-0021 is a medium vulnerability (CVSS 5.0) in Ntp, published January 7, 2009. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 3.22%, the 88th percentile. Fixed in ntp 1:4.2.4p4+dfsg-8.
References
support.apple.com/kb/HT3549
securityfocus.com/archive/1/499827/100/0/threaded
securitytracker.com/id?1021533
lists.ntp.org/pipermail/announce/2009-January/000055.html
secunia.com/advisories/34642
redhat.com/support/errata/RHSA-2009-0046.html
Show 22 moreShow less
lists.apple.com/archives/security-announce/2009/May/msg00002.html
lists.opensuse.org/opensuse-security-announce/2009-03/msg00000.html
ocert.org/advisories/ocert-2008-016.html
slackware.com/security/viewer.php?l=slackware-security&y=2009&m=slackware-security.531177
us-cert.gov/cas/techalerts/TA09-133A.html
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10035
vupen.com/english/advisories/2009/1297
nvd.nist.gov/vuln/detail/CVE-2009-0021
github.com/advisories/GHSA-4q4m-qx69-vcgq
security-tracker.debian.org/tracker/CVE-2009-0021
access.redhat.com/errata/RHSA-2009:0046
bugzilla.redhat.com/show_bug.cgi?id=476807
security.access.redhat.com/data/csaf/v2/advisories/2009/rhsa-2009_0046.json
cve.org/CVERecord?id=CVE-2009-0021