5

CVE-2009-0021: ntp Improper Authentication

CVSS: 5.0v2.0MediumModified
AliasesRHSA-2009:0046DEBIAN-CVE-2009-0021DSA-1702-1
Published 07-01-2009Last modified 07-08-2024
Open JSON

Vulnerability summary

CVE-2009-0021 is a medium (CVSS 5.0) Improper Authentication vulnerability in ntp. EPSS estimates a 3.22% chance of exploitation in the next 30 days, higher than 88% of scored vulnerabilities.

Overall risk
21/100
0100
Low · default modelHow is this calculated?
CVSS score
5.0/10
010
Medium · v2.0 (NVD)
EPSS score
3.22%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 07-01-2009
    PublishedVulnerability first disclosed.
  2. 07-08-2024
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

1 score · 1 source · 1 version

EPSS trend

Probability

3.22%

Chance of exploitation in the next 30 days

Percentile

88%

Versus all other CVEs

30-day change

0.00 pp

From 3.22% on 18-09-2026

18-09-202618-10-2026
EPSS score
3.22%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Redhat2 products
  • ntp< 0:4.2.0.a.20040617-8.el4_7.1 | < 0:4.2.2p1-9.el5_3.1
  • ntp-debuginfo< 0:4.2.0.a.20040617-8.el4_7.1 | < 0:4.2.2p1-9.el5_3.1
Debian1 product
  • ntp< 1:4.2.4p4+dfsg-8 | < 1:4.2.2.p4+dfsg-2etch1
Ntp1 product
  • ntp≤ 4.2.4p4 | 4.2.0 | 4.2.2 | 4.2.4p1 | 4.2.4p2 | 4.2.4p3

3 vendors · 4 products

References

27 links
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