[ GLSA 200810-03 ] libspf2: DNS response buffer overflow

[GLSA]

Gentoo Linux Security Advisory

Title: libspf2: DNS response buffer overflow (GLSA 200810-03)
Severity: high
Exploitable: remote
Date: October 30, 2008
Bug(s): #242254
ID: 200810-03

Synopsis


A memory management error in libspf2 might allow for remote execution of
arbitrary code.


Background


libspf2 is a library that implements the Sender Policy Framework,
allowing mail transfer agents to make sure that an email is authorized
by the domain name that it is coming from. Currently, only the exim MTA
uses libspf2 in Gentoo.


Affected Packages

Package: mail-filter/libspf2
Vulnerable: < 1.2.8
Unaffected: >= 1.2.8
Architectures: All supported architectures


Description


libspf2 uses a fixed-length buffer to receive DNS responses and does
not properly check the length of TXT records, leading to buffer
overflows.


Impact


A remote attacker could store a specially crafted DNS entry and entice
a user or automated system using libspf2 to lookup that SPF entry (e.g.
by sending an email to the MTA), possibly allowing for the execution of
arbitrary code.


Workaround


There is no known workaround at this time.


Resolution


All libspf2 users should upgrade to the latest version: