CVE-2008-4109: Race Condition

Published Sep 17, 2008
·
Updated

A certain Debian patch for OpenSSH before 4.3p2-9etch3 on etch; before 4.6p1-1 on sid and lenny; and on other distributions such as SUSE uses functions that are not async-signal-safe in the signal handler for login timeouts, which allows remote attackers to cause a denial of service (connection slot exhaustion) via multiple login attempts. NOTE: this issue exists because of an incorrect fix for CVE-2006-5051.

Affected Software

203 affected components
Debian Linux=unknown-unknown
OpenBSD OpenSSH<=4.3p2
OpenBSD OpenSSH=1.2
OpenBSD OpenSSH=1.2.1
OpenBSD OpenSSH=1.2.2
OpenBSD OpenSSH=1.2.3
OpenBSD OpenSSH=1.2.27
OpenBSD OpenSSH=1.3
OpenBSD OpenSSH=1.5
OpenBSD OpenSSH=1.5.7
OpenBSD OpenSSH=1.5.8
OpenBSD OpenSSH=2
OpenBSD OpenSSH=2.1
OpenBSD OpenSSH=2.1.1
OpenBSD OpenSSH=2.2
OpenBSD OpenSSH=2.3
OpenBSD OpenSSH=2.3.1
OpenBSD OpenSSH=2.5
OpenBSD OpenSSH=2.5.1
OpenBSD OpenSSH=2.5.2
OpenBSD OpenSSH=2.9
OpenBSD OpenSSH=2.9.9
OpenBSD OpenSSH=2.9.9p2
OpenBSD OpenSSH=2.9p1
OpenBSD OpenSSH=2.9p2
OpenBSD OpenSSH=3.0
OpenBSD OpenSSH=3.0.1
OpenBSD OpenSSH=3.0.1p1
OpenBSD OpenSSH=3.0.2
OpenBSD OpenSSH=3.0.2p1
OpenBSD OpenSSH=3.0p1
OpenBSD OpenSSH=3.1
OpenBSD OpenSSH=3.1p1
OpenBSD OpenSSH=3.2
OpenBSD OpenSSH=3.2.2
OpenBSD OpenSSH=3.2.2p1
OpenBSD OpenSSH=3.2.3p1
OpenBSD OpenSSH=3.3
OpenBSD OpenSSH=3.3p1
OpenBSD OpenSSH=3.4
OpenBSD OpenSSH=3.4p1
OpenBSD OpenSSH=3.5
OpenBSD OpenSSH=3.5p1
OpenBSD OpenSSH=3.6
OpenBSD OpenSSH=3.6.1
OpenBSD OpenSSH=3.6.1p1
OpenBSD OpenSSH=3.6.1p2
OpenBSD OpenSSH=3.7
OpenBSD OpenSSH=3.7.1
OpenBSD OpenSSH=3.7.1p1
OpenBSD OpenSSH=3.7.1p2
OpenBSD OpenSSH=3.8
OpenBSD OpenSSH=3.8.1
OpenBSD OpenSSH=3.8.1p1
OpenBSD OpenSSH=3.9
OpenBSD OpenSSH=3.9.1
OpenBSD OpenSSH=3.9.1p1
OpenBSD OpenSSH=4.0
OpenBSD OpenSSH=4.0p1
OpenBSD OpenSSH=4.1
OpenBSD OpenSSH=4.1p1
OpenBSD OpenSSH=4.2
OpenBSD OpenSSH=4.2p1
OpenBSD OpenSSH=4.3
OpenBSD OpenSSH=4.3p1
Debian Linux=unknown-unknown
OpenBSD OpenSSH<=4.6
OpenBSD OpenSSH=4.3p2
OpenBSD OpenSSH=4.4
OpenBSD OpenSSH=4.4p1
All of the following
Debian Linux=unknown-unknown
Any of the following
OpenBSD OpenSSH<=4.3p2
OpenBSD OpenSSH=1.2
OpenBSD OpenSSH=1.2.1
OpenBSD OpenSSH=1.2.2
OpenBSD OpenSSH=1.2.3
OpenBSD OpenSSH=1.2.27
OpenBSD OpenSSH=1.3
OpenBSD OpenSSH=1.5
OpenBSD OpenSSH=1.5.7
OpenBSD OpenSSH=1.5.8
OpenBSD OpenSSH=2
OpenBSD OpenSSH=2.1
OpenBSD OpenSSH=2.1.1
OpenBSD OpenSSH=2.2
OpenBSD OpenSSH=2.3
OpenBSD OpenSSH=2.3.1
OpenBSD OpenSSH=2.5
OpenBSD OpenSSH=2.5.1
OpenBSD OpenSSH=2.5.2
OpenBSD OpenSSH=2.9
OpenBSD OpenSSH=2.9.9
OpenBSD OpenSSH=2.9.9p2
OpenBSD OpenSSH=2.9p1
OpenBSD OpenSSH=2.9p2
OpenBSD OpenSSH=3.0
OpenBSD OpenSSH=3.0.1
OpenBSD OpenSSH=3.0.1p1
OpenBSD OpenSSH=3.0.2
OpenBSD OpenSSH=3.0.2p1
OpenBSD OpenSSH=3.0p1
OpenBSD OpenSSH=3.1
OpenBSD OpenSSH=3.1p1
OpenBSD OpenSSH=3.2
OpenBSD OpenSSH=3.2.2
OpenBSD OpenSSH=3.2.2p1
OpenBSD OpenSSH=3.2.3p1
OpenBSD OpenSSH=3.3
OpenBSD OpenSSH=3.3p1
OpenBSD OpenSSH=3.4
OpenBSD OpenSSH=3.4p1
OpenBSD OpenSSH=3.5
OpenBSD OpenSSH=3.5p1
OpenBSD OpenSSH=3.6
OpenBSD OpenSSH=3.6.1
OpenBSD OpenSSH=3.6.1p1
OpenBSD OpenSSH=3.6.1p2
OpenBSD OpenSSH=3.7
OpenBSD OpenSSH=3.7.1
OpenBSD OpenSSH=3.7.1p1
OpenBSD OpenSSH=3.7.1p2
OpenBSD OpenSSH=3.8
OpenBSD OpenSSH=3.8.1
OpenBSD OpenSSH=3.8.1p1
OpenBSD OpenSSH=3.9
OpenBSD OpenSSH=3.9.1
OpenBSD OpenSSH=3.9.1p1
OpenBSD OpenSSH=4.0
OpenBSD OpenSSH=4.0p1
OpenBSD OpenSSH=4.1
OpenBSD OpenSSH=4.1p1
OpenBSD OpenSSH=4.2
OpenBSD OpenSSH=4.2p1
OpenBSD OpenSSH=4.3
OpenBSD OpenSSH=4.3p1
All of the following
Debian Linux=unknown-unknown
Any of the following
OpenBSD OpenSSH<=4.6
OpenBSD OpenSSH=1.2
OpenBSD OpenSSH=1.2.1
OpenBSD OpenSSH=1.2.2
OpenBSD OpenSSH=1.2.3
OpenBSD OpenSSH=1.2.27
OpenBSD OpenSSH=1.3
OpenBSD OpenSSH=1.5
OpenBSD OpenSSH=1.5.7
OpenBSD OpenSSH=1.5.8
OpenBSD OpenSSH=2
OpenBSD OpenSSH=2.1
OpenBSD OpenSSH=2.1.1
OpenBSD OpenSSH=2.2
OpenBSD OpenSSH=2.3
OpenBSD OpenSSH=2.3.1
OpenBSD OpenSSH=2.5
OpenBSD OpenSSH=2.5.1
OpenBSD OpenSSH=2.5.2
OpenBSD OpenSSH=2.9
OpenBSD OpenSSH=2.9.9
OpenBSD OpenSSH=2.9.9p2
OpenBSD OpenSSH=2.9p1
OpenBSD OpenSSH=2.9p2
OpenBSD OpenSSH=3.0
OpenBSD OpenSSH=3.0.1
OpenBSD OpenSSH=3.0.1p1
OpenBSD OpenSSH=3.0.2
OpenBSD OpenSSH=3.0.2p1
OpenBSD OpenSSH=3.0p1
OpenBSD OpenSSH=3.1
OpenBSD OpenSSH=3.1p1
OpenBSD OpenSSH=3.2
OpenBSD OpenSSH=3.2.2
OpenBSD OpenSSH=3.2.2p1
OpenBSD OpenSSH=3.2.3p1
OpenBSD OpenSSH=3.3
OpenBSD OpenSSH=3.3p1
OpenBSD OpenSSH=3.4
OpenBSD OpenSSH=3.4p1
OpenBSD OpenSSH=3.5
OpenBSD OpenSSH=3.5p1
OpenBSD OpenSSH=3.6
OpenBSD OpenSSH=3.6.1
OpenBSD OpenSSH=3.6.1p1
OpenBSD OpenSSH=3.6.1p2
OpenBSD OpenSSH=3.7
OpenBSD OpenSSH=3.7.1
OpenBSD OpenSSH=3.7.1p1
OpenBSD OpenSSH=3.7.1p2
OpenBSD OpenSSH=3.8
OpenBSD OpenSSH=3.8.1
OpenBSD OpenSSH=3.8.1p1
OpenBSD OpenSSH=3.9
OpenBSD OpenSSH=3.9.1
OpenBSD OpenSSH=3.9.1p1
OpenBSD OpenSSH=4.0
OpenBSD OpenSSH=4.0p1
OpenBSD OpenSSH=4.1
OpenBSD OpenSSH=4.1p1
OpenBSD OpenSSH=4.2
OpenBSD OpenSSH=4.2p1
OpenBSD OpenSSH=4.3
OpenBSD OpenSSH=4.3p1
OpenBSD OpenSSH=4.3p2
OpenBSD OpenSSH=4.4
OpenBSD OpenSSH=4.4p1

Remediation

Patch Available

http://www.debian.org/security/2008/dsa-1638

Event History

Sep 17, 2008
CVE Published
via MITRE·06:06 PM
Data Sourced
via MITRE·06:06 PM
Description
Sep 18, 2008
Data Sourced
03:04 PM
DescriptionWeaknessAffected Software
Jul 1, 2024
News Published
via BleepingComputer·01:37 PM
News Published
via BleepingComputer·01:38 PM
News Published
via The Register·02:01 PM
News Published
via The Register·02:05 PM
Jul 2, 2024
News Published
via ZDNet·01:02 PM
Jul 6, 2024
News Published
via ZDNet·02:24 PM
Apr 24, 2025
Known Exploited
07:55 PM

Peer vulnerabilities

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Frequently Asked Questions

1

What is the severity of CVE-2008-4109?

CVE-2008-4109 is classified as a denial of service vulnerability affecting OpenSSH.

2

How do I fix CVE-2008-4109?

To fix CVE-2008-4109, upgrade OpenSSH to version 4.3p2 or later if using Debian or relevant distributions.

3

What versions of OpenSSH are affected by CVE-2008-4109?

CVE-2008-4109 affects OpenSSH versions prior to 4.3p2, including versions 1.2 through 4.3.

4

Can CVE-2008-4109 lead to remote exploitation?

No, CVE-2008-4109 does not allow remote execution of code; it only allows denial of service.

5

Is there a workaround for CVE-2008-4109?

There is no effective workaround for CVE-2008-4109 other than upgrading to a safe version of OpenSSH.

Company

Resources

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