GNU shtool, ocaml-mysql: Insecure temporary file creation

1. Gentoo Linux Security Advisory

Advisory Reference	GLSA 200506-08 / GNU shtool
Release Date	June 11, 2005
Latest Revision	June 11, 2005: 01
Impact	normal
Exploitable	local

Package	Vulnerable versions	Unaffected versions	Architecture(s)
dev-util/shtool	< 2.0.1-r2	>= 2.0.1-r2	All supported architectures
dev-ml/ocaml-mysql	< 1.0.3-r1	>= 1.0.3-r1	All supported architectures

Related bugreports: #93782, #93784

Synopsis

GNU shtool and ocaml-mysql are vulnerable to symlink attacks, potentially allowing a local user to overwrite arbitrary files.

2. Impact Information

Background

GNU shtool is a compilation of small shell scripts into a single shell tool. The ocaml-mysql package includes the GNU shtool code.

Description

Eric Romang has discovered that GNU shtool insecurely creates temporary files with predictable filenames (CAN-2005-1751). On closer inspection, Gentoo Security discovered that the shtool temporary file, once created, was being reused insecurely (CAN-2005-1759).

Impact

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

3. Resolution Information

Workaround

There is no known workaround at this time.

Resolution

All GNU shtool users should upgrade to the latest version:

Code Listing 3.1: Resolution

# emerge --sync
# emerge --ask --oneshot --verbose ">=dev-util/shtool-2.0.1-r2"

All ocaml-mysql users should upgrade to the latest version:

Code Listing 3.2: Resolution

# emerge --sync
# emerge --ask --oneshot --verbose ">=dev-ml/ocaml-mysql-1.0.3-r1"

4. References

Page updated June 11, 2005

Summary: This is a Gentoo Linux Security Advisory

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