daemon/worker.c in Unbound 1.x before 1.4.10, when debugging functionality and the interface-automatic option are enabled, allows remote attackers to cause a denial of service (assertion failure and daemon exit) via a crafted DNS request that triggers improper error handling.

The remote host is affected by the vulnerability described in GLSA-201110-12 (Unbound: Denial of Service)

    Multiple vulnerabilities have been discovered in unbound. Please review       the CVE identifiers referenced below for details.
  Impact :

    A remote attacker could cause a Denial of Service.
  Workaround :

    There is no known workaround at this time.

According to its self-reported version number, the remote Unbound DNS resolver is affected by a denial of service vulnerability due improper error handling. An unauthenticated, remote attacker can exploit this, via a specially crafted DNS request, to cause an assertion failure and a daemon exit, resulting in a denial of service condition. Note that this vulnerability only exists when debugging functionality is enabled (e.g. --enable-checking' or '--enable-debug') and the interface-automatic option is turned on.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Denial of Service fix: CVE-2011-1922.

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Unbound developer reports :

NLnet Labs was notified of an error in Unbound's code-path for error replies which is triggered under special conditions. The error causes the program to abort.

ID	Name	Product	Family	Severity
56524	GLSA-201110-12 : Unbound: Denial of Service	Nessus	Gentoo Local Security Checks	medium
55049	Unbound < 1.4.10 daemon/worker.c DNS Request Error Handling DoS	Nessus	DNS	medium
54978	Fedora 14 : unbound-1.4.8-2.fc14 (2011-7555)	Nessus	Fedora Local Security Checks	medium
54825	FreeBSD : Unbound -- an empty error packet handling assertion failure (dc96ac1f-86b1-11e0-9e85-00215af774f0)	Nessus	FreeBSD Local Security Checks	medium

Detections

Analytics

CVE-2011-1922

high

Tenable Plugins

medium

medium

medium

medium