CVE-2012-6109 Rack vulnerable to REDoS

What is CVE-2012-6109?

CVE-2012-6109 is a medium-severity denial of service vulnerability in n/a, published on 1 Mar 2013. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

lib/rack/multipart.rb in Rack before 1.1.4, 1.2.x before 1.2.6, 1.3.x before 1.3.7, and 1.4.x before 1.4.2 uses an incorrect regular expression, which allows remote attackers to cause a denial of service (infinite loop) via a crafted Content-Disposion header.

Which versions are affected by CVE-2012-6109?

8 open source packages ship an affected version, including rack. It affects 1 product.

Products include Rack Project Rack.

How do I fix CVE-2012-6109?

Upgrade rack to a fixed version for your release line: 1.1.4, 1.2.6, 1.3.7 or 1.4.2.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2012-6109 being exploited?

There is no known exploitation of CVE-2012-6109 in the wild and no public exploit code.

Other vulnerabilities in n/a

• CVE-2018-16470 Rack vulnerable to Denial of Service High 7.5
• CVE-2013-0263 Rack arbitrary code execution via timing attack Medium 5.1
• CVE-2013-0183 Rack rubygems receiving excessively long lines triggers out-of-memory error Medium 5.0
• CVE-2011-5036 Rack Gem Subject to Denial of Service via Hash Collisions Medium 5.0
• CVE-2013-0184 Rack vulnerable to Denial of Service Medium 4.3

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2012-6109, GHSA-h77x-m5q8-c29h, UBUNTU-CVE-2012-6109.