f2c: Insecure temporary file creation

1. Gentoo Linux Security Advisory

Advisory Reference	GLSA 200501-43 / f2c
Release Date	January 30, 2005
Latest Revision	January 30, 2005: 01
Impact	normal
Exploitable	local

Package	Vulnerable versions	Unaffected versions	Architecture(s)
dev-lang/f2c	<= 20030320	>= 20030320-r1	All supported architectures

Related bugreports: #79725

Synopsis

f2c is vulnerable to symlink attacks, potentially allowing a local user to overwrite arbitrary files.

2. Impact Information

Background

f2c is a Fortran to C translator. Portage uses this package in some ebuilds to build Fortran sources.

Description

Javier Fernandez-Sanguino Pena from the Debian Security Audit Team discovered that f2c creates temporary files in world-writeable directories with predictable names.

Impact

A local attacker could create symbolic links in the temporary files directory, pointing to a valid file somewhere on the filesystem. When f2c is executed, this would result in the file being overwritten with the rights of the user running the software, which could be the root user.

3. Resolution Information

Workaround

There is no known workaround at this time.

Resolution

All f2c users should upgrade to the latest version:

Code Listing 3.1: Resolution

# emerge --sync
# emerge --ask --oneshot --verbose ">=dev-lang/f2c-20030320-r1"

4. References

CAN-2005-0017

Updated January 30, 2005

Summary: This is a Gentoo Linux Security Advisory

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