CVE-2009-0021 Security feature bypass in n/a

Medium 5.0 Published 7 Jan 2009 Updated 7 Aug 2024

Remote attackers can bypass SSL/TLS certificate validation in NTP by exploiting improper return value checks in OpenSSL verification functions.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2009-0021?

CVE-2009-0021 is a medium-severity vulnerability in Ntp Ntp, published on 7 Jan 2009. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Weakness: CWE-287

Which versions are affected by CVE-2009-0021?

It affects 1 product.

Linux distribution packages (12)

`ntp` Red Hat:enterprise_linux:4::as	All versions	`0:4.2.0.a.20040617-8.el4_7.1`
`ntp-debuginfo` Red Hat:enterprise_linux:4::as	All versions	`0:4.2.0.a.20040617-8.el4_7.1`
`ntp` Red Hat:enterprise_linux:4::desktop	All versions	`0:4.2.0.a.20040617-8.el4_7.1`
`ntp-debuginfo` Red Hat:enterprise_linux:4::desktop	All versions	`0:4.2.0.a.20040617-8.el4_7.1`
`ntp` Red Hat:enterprise_linux:4::es	All versions	`0:4.2.0.a.20040617-8.el4_7.1`
`ntp-debuginfo` Red Hat:enterprise_linux:4::es	All versions	`0:4.2.0.a.20040617-8.el4_7.1`
`ntp` Red Hat:enterprise_linux:4::ws	All versions	`0:4.2.0.a.20040617-8.el4_7.1`
`ntp-debuginfo` Red Hat:enterprise_linux:4::ws	All versions	`0:4.2.0.a.20040617-8.el4_7.1`
`ntp` Red Hat:enterprise_linux:5::client	All versions	`0:4.2.2p1-9.el5_3.1`
`ntp-debuginfo` Red Hat:enterprise_linux:5::client	All versions	`0:4.2.2p1-9.el5_3.1`
`ntp` Red Hat:enterprise_linux:5::server	All versions	`0:4.2.2p1-9.el5_3.1`
`ntp-debuginfo` Red Hat:enterprise_linux:5::server	All versions	`0:4.2.2p1-9.el5_3.1`

Products include Ntp Ntp.

How do I fix CVE-2009-0021?

Upgrade to a fixed version.

Is CVE-2009-0021 being exploited?

There is no known exploitation of CVE-2009-0021 in the wild and no public exploit code.

All Ntp Ntp vulnerabilities

Sources

Also known as DEBIAN-CVE-2009-0021, DSA-1702-1, GHSA-4q4m-qx69-vcgq, RHSA-2009:0046.