REDHAT-BUG-2543005: Medium severity Debian dash vulnerability
A flaw was found in dash. When built without libc fnmatch, the internal pmatch() matcher implements by unbounded recursion over candidate positions. A local user who can plant filenames, or otherwise feed that matcher, can make a short multi-star pattern such as .....tar.gz consume excessive CPU.
Affected Software
Event History
Frequently Asked Questions
Who is realistically exposed to this issue?
Systems using Debian dash built without libc fnmatch are exposed when a local user can create filenames or otherwise supply input that reaches dash's internal pmatch() matcher.
What does an attacker need to exploit the flaw?
The attacker needs local ability to plant crafted filenames or otherwise feed a glob pattern to the matcher. A short pattern containing multiple asterisks, such as *.*.*.*.*.tar.gz, can trigger excessive CPU consumption.
What is the expected impact of successful exploitation?
Successful exploitation causes excessive CPU consumption due to unbounded recursive matching. The provided information describes a local denial-of-service condition rather than code execution or privilege escalation.