The leafnode server in leafnode 1.9.20 to 1.9.29 allows remote attackers to cause a denial of service (infinite loop) when leafnode requests a cross-posted article to one group whose name is a prefix of another group.

According to its version number, the remote Leafnode NNTP server is vulnerable to a denial of service attack.  Specifically, it may go into an infinite loop with 100% CPU use when an article that has been crossposted to several groups, one of which is the prefix of another, and when this article is then requested by its Message-ID. 

Note that Nessus did not actually test for the flaw but instead has relied on the version in Leafnode's banner so this may be a false positive.

The leafnode NNTP server may go into an unterminated loop with 100% CPU use when an article is requested by Message-ID that has been crossposted to several news groups when one of the group names is the prefix of another group name that the article was cross-posted to.
Found by Jan Knutar.

The remote host is running the LeafNode NNTP server. The version of LeafNode that is installed is vulnerable to a denial of service attack that may be abused by an attacker to cause this system to fail.

A vulnerability was discovered by Jan Knutar in leafnode that Mark Brown pointed out could be used in a Denial of Service attack. This vulnerability causes leafnode to go into an infinite loop with 100% CPU use when an article that has been crossposed to several groups, one of which is the prefix of another, is requested by it's Message-ID.

This vulnerability was introduced in 1.9.20 and fixed upstream in version 1.9.30. Only Mandrake Linux 9.0 is affected by this, but version 1.9.19 (which shipped with Mandrake Linux 8.2) is receiving an update due to critical bugs in it that can corrupt parts of its news spool under certain circumstances.

ID	Name	Product	Family	Type	Severity
42259	leafnode Cross-Posted Article Group Name Prefix DoS	Nessus	Misc.	Remote	medium
19177	FreeBSD : leafnode denial-of-service triggered by article request (f7a3b18c-624c-4703-9756-b6b27429e5b0)	Nessus	FreeBSD Local Security Checks	Local	medium
1887	LeafNode < 1.9.30 Resource Exhaustion DoS	Nessus Network Monitor	Generic		medium
13990	Mandrake Linux Security Advisory : leafnode (MDKSA-2003:005)	Nessus	Mandriva Local Security Checks	Local	medium

Detections

Analytics

CVE-2002-1661

high

Tenable Plugins

medium

medium

medium

medium