Gentoo Logo

ed: Insecure temporary file handling


1.  Gentoo Linux Security Advisory

Version Information

Advisory Reference GLSA 200410-07 / ed
Release Date October 09, 2004
Latest Revision October 09, 2004: 01
Impact normal
Exploitable local
Package Vulnerable versions Unaffected versions Architecture(s)
sys-apps/ed <= 0.2-r3 >= 0.2-r4 All supported architectures

Related bugreports: #66400


The ed utility is vulnerable to symlink attacks, potentially allowing a local user to overwrite or change rights on arbitrary files with the rights of the user running ed, which could be the root user.

2.  Impact Information


ed is a line-oriented text editor, used to create or modify text files, both interactively and via shell scripts.


ed insecurely creates temporary files in world-writeable directories with predictable names. Given that ed is used in various system shell scripts, they are by extension affected by the same vulnerability.


A local attacker could create symbolic links in the temporary files directory, pointing to a valid file somewhere on the filesystem. When ed is called, this would result in file access with the rights of the user running the utility, which could be the root user.

3.  Resolution Information


There is no known workaround at this time.


All ed users should upgrade to the latest version:

Code Listing 3.1: Resolution

# emerge sync
# emerge -pv ">=sys-apps/ed-0.2-r4"
# emerge ">=sys-apps/ed-0.2-r4"

4.  References


Page updated October 09, 2004

Summary: This is a Gentoo Linux Security Advisory

Security Team
Contact Address

Donate to support our development efforts.

Copyright 2001-2015 Gentoo Foundation, Inc. Questions, Comments? Contact us.