Dnsmasq: Multiple vulnerabilities — GLSA 200909-19

Multiple vulnerabilities in Dnsmasq might result in the remote execution of arbitrary code, or a Denial of Service.

Affected packages

Background

Dnsmasq is a lightweight, easy to configure DNS forwarder and DHCP server. It includes support for Trivial FTP (TFTP).

Description

Multiple vulnerabilities have been reported in the TFTP functionality included in Dnsmasq:

• Pablo Jorge and Alberto Solino discovered a heap-based buffer overflow (CVE-2009-2957).
• An anonymous researcher reported a NULL pointer reference (CVE-2009-2958).

Impact

A remote attacker in the local network could exploit these vulnerabilities by sending specially crafted TFTP requests to a machine running Dnsmasq, possibly resulting in the remote execution of arbitrary code with the privileges of the user running the daemon, or a Denial of Service. NOTE: The TFTP server is not enabled by default.

Workaround

You can disable the TFTP server either at buildtime by not enabling the "tftp" USE flag, or at runtime. Make sure "--enable-tftp" is not set in the DNSMASQ_OPTS variable in the /etc/conf.d/dnsmasq file and "enable-tftp" is not set in /etc/dnsmasq.conf, either of which would enable TFTP support if it is compiled in.

Resolution

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=net-dns/dnsmasq-2.5.0"

References

• CVE-2009-2957
• CVE-2009-2958

Release date
September 20, 2009

Latest revision
September 20, 2009: 01

Severity
normal

Exploitable
remote

Bugzilla entries

• 282653