[ GLSA 200410-07 ] ed: Insecure temporary file handling

[GLSA]

Gentoo Linux Security Advisory

Title: ed: Insecure temporary file handling (GLSA 200410-07)
Severity: normal
Exploitable: local
Date: October 09, 2004
Bug(s): #66400
ID: 200410-07

Synopsis

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.

Background

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

Affected Packages

Package: sys-apps/ed
Vulnerable: <= 0.2-r3
Unaffected: >= 0.2-r4
Architectures: All supported architectures


Description

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.

Impact

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.

Workaround

There is no known workaround at this time.

Resolution

All ed users should upgrade to the latest version: