RHSA-2007:0018 - Security Advisory

Topic

Updated fetchmail packages that fix two security issues are now available.

This update has been rated as having moderate security impact by the Red
Hat Security Response Team.

Description

Fetchmail is a remote mail retrieval and forwarding utility.

A denial of service flaw was found when Fetchmail was run in multidrop
mode. A malicious mail server could send a message without headers which
would cause Fetchmail to crash (CVE-2005-4348). This issue did not affect
the version of Fetchmail shipped with Red Hat Enterprise Linux 2.1 or 3.

A flaw was found in the way Fetchmail used TLS encryption to connect to
remote hosts. Fetchmail provided no way to enforce the use of TLS
encryption and would not authenticate POP3 protocol connections properly
(CVE-2006-5867). This update corrects this issue by enforcing TLS
encryption when the "sslproto" configuration directive is set to "tls1".

Users of Fetchmail should update to these packages, which contain
backported patches to correct these issues.

Note: This update may break configurations which assumed that Fetchmail
would use plain-text authentication if TLS encryption is not supported by
the POP3 server even if the "sslproto" directive is set to "tls1". If you
are using a custom configuration that depended on this behavior you will
need to modify your configuration appropriately after installing this update.

Solution

Before applying this update, make sure all previously released errata
relevant to your system have been applied.

This update is available via Red Hat Network. To use Red Hat Network,
launch the Red Hat Update Agent with the following command:

up2date

This will start an interactive process that will result in the appropriate
RPMs being upgraded on your system.

Affected Products

• Red Hat Enterprise Linux Server 4 x86_64
• Red Hat Enterprise Linux Server 4 ia64
• Red Hat Enterprise Linux Server 4 i386
• Red Hat Enterprise Linux Server 3 x86_64
• Red Hat Enterprise Linux Server 3 ia64
• Red Hat Enterprise Linux Server 3 i386
• Red Hat Enterprise Linux Server 2 ia64
• Red Hat Enterprise Linux Server 2 i386
• Red Hat Enterprise Linux Workstation 4 x86_64
• Red Hat Enterprise Linux Workstation 4 ia64
• Red Hat Enterprise Linux Workstation 4 i386
• Red Hat Enterprise Linux Workstation 3 x86_64
• Red Hat Enterprise Linux Workstation 3 ia64
• Red Hat Enterprise Linux Workstation 3 i386
• Red Hat Enterprise Linux Workstation 2 ia64
• Red Hat Enterprise Linux Workstation 2 i386
• Red Hat Enterprise Linux Desktop 4 x86_64
• Red Hat Enterprise Linux Desktop 4 i386
• Red Hat Enterprise Linux Desktop 3 x86_64
• Red Hat Enterprise Linux Desktop 3 i386
• Red Hat Enterprise Linux for IBM z Systems 4 s390x
• Red Hat Enterprise Linux for IBM z Systems 4 s390
• Red Hat Enterprise Linux for IBM z Systems 3 s390x
• Red Hat Enterprise Linux for IBM z Systems 3 s390
• Red Hat Enterprise Linux for Power, big endian 4 ppc
• Red Hat Enterprise Linux for Power, big endian 3 ppc

Fixes

• BZ - 176266 - CVE-2005-4348 Fetchmail DOS by malicious server in multidrop mode
• BZ - 221981 - CVE-2006-5867 fetchmail not enforcing TLS for POP3 properly

CVEs

• CVE-2005-4348
• CVE-2006-5867

References

• http://fetchmail.berlios.de/fetchmail-SA-2005-03.txt
• http://fetchmail.berlios.de/fetchmail-SA-2006-03.txt
• http://www.redhat.com/security/updates/classification/#moderate