USN-260-1: flex vulnerability

Publication date

7 March 2006

Overview

flex vulnerability


Details

Chris Moore discovered a buffer overflow in a particular class of
lexicographical scanners generated by flex. This could be exploited to
execute arbitrary code by processing specially crafted user-defined
input to an application that uses a flex scanner for parsing.

This flaw particularly affects gpc, the GNU Pascal Compiler. A
potentially remote attacker could exploit this by tricking an user or
automated system into compiling a specially crafted Pascal source code
file.

Please note that gpc is not officially supported in Ubuntu (it is in
the 'universe' component of the archive). However, this affects you if
you use a customized version built from the gcc-3.3 or gcc-3.4 source
package (which is supported).

Chris Moore discovered a buffer overflow in a particular class of
lexicographical scanners generated by flex. This could be exploited to
execute arbitrary code by processing specially crafted user-defined
input to an application that uses a flex scanner for parsing.

This flaw particularly affects gpc, the GNU Pascal Compiler. A
potentially remote attacker could exploit this by tricking an user or
automated system into compiling a specially crafted Pascal source code
file.

Please note that gpc is not officially supported in Ubuntu (it is in
the 'universe' component of the archive). However, this affects you if
you use a customized version built from the gcc-3.3 or gcc-3.4 source
package (which is supported).

Update instructions

In general, a standard system update will make all the necessary changes.

Learn more about how to get the fixes.

The problem can be corrected by updating your system to the following package versions:

Ubuntu Release Package Version
5.10 breezy flex – 
gpc-2.1-3.4 – 
gpc-2.1-3.3 – 
5.04 hoary flex – 
gpc-2.1-3.4 – 
gpc-2.1-3.3 – 
4.10 warty flex – 
gpc-2.1-3.4 – 
gpc-2.1-3.3 – 

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