CVE-2021-32763 Regular Expression Denial of Service in OpenProject forum messages
An attacker can cause a denial of service in OpenProject forums by submitting messages with unterminated pre tags that trigger excessive regex backtracking.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-32763?
CVE-2021-32763 is a medium-severity denial of service vulnerability in opf openproject, published on 20 Jul 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
OpenProject is open-source, web-based project management software. In versions prior to 11.3.3, the `MessagesController` class of OpenProject has a `quote` method that implements the logic behind the Quote button in the discussion forums, and it uses a regex to strip `<pre>` tags from the message being quoted. The `(.|\s)` part can match a space character in two ways, so an unterminated `<pre>` tag containing `n` spaces causes Ruby's regex engine to backtrack to try 2<sup>n</sup> states in the NFA. This will result in a Regular Expression Denial of Service. The issue is fixed in OpenProject 11.3.3. As a workaround, one may install the patch manually.
Weakness: CWE-400
Which versions are affected by CVE-2021-32763?
It affects 1 product.
Products include Openproject Openproject.
How do I fix CVE-2021-32763?
No fix has been published for CVE-2021-32763 yet. Limit exposure of the affected software until one is available.
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-2021-32763 being exploited?
There is no known exploitation of CVE-2021-32763 in the wild and no public exploit code.
Other vulnerabilities in opf openproject
- CVE-2026-34717 OpenProject: SQL Injection in Cost Reporting =n Operator via parse_number_string
- CVE-2026-25763 Command Injection on OpenProject repositories leads to Remote Code Execution
- CVE-2026-24685 OpenProject has Argument Injection on Repository module that allows Arbitrary File Write
- CVE-2026-32698 OpenProject has a SQL Injection via Custom Field Name that can be chained to Remote Code Execution
- CVE-2026-32703 OpenProject's repository files are served with the MIME type allowing them to be used to bypass Content Security Policy
Sources
Also known as GHSA-qqvp-j6gm-q56f.