CVE-2021-32837 mechanize vulnerable to ReDoS
A malicious web server can cause the mechanize library to crash via a regular expression denial of service attack.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-32837?
CVE-2021-32837 is a high-severity denial of service vulnerability in python-mechanize mechanize, published on 17 Jan 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
mechanize, a library for automatically interacting with HTTP web servers, contains a regular expression that is vulnerable to regular expression denial of service (ReDoS) prior to version 0.4.6. If a web server responds in a malicious way, then mechanize could crash. Version 0.4.6 has a patch for the issue.
Weakness: CWE-1333
Which versions are affected by CVE-2021-32837?
3 open source packages ship an affected version, including mechanize. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
mechanize PyPI | All versions | 0.4.6 |
mechanize PyPI | All versions | 0.4.6 |
mechanize PyPI | All versions | 0.4.6 |
Linux distribution packages (3)
python-mechanize SUSE:Package Hub 15 SP4 | All versions | 0.4.8-bp154.2.3.1 |
python-mechanize openSUSE:Leap 15.4 | All versions | 0.4.8-bp154.2.3.1 |
python-mechanize openSUSE:Tumbleweed | All versions | 0.4.10-1.4 |
Products include Mechanize Project Mechanize.
How do I fix CVE-2021-32837?
Upgrade mechanize to 0.4.6 or later.
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-2021-32837 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-32837 exists.
Sources
Also known as DEBIAN-CVE-2021-32837, DLA-3460-1, DLA-4418-1, GHSA-g3pv-pj5f-3hfq, MGASA-2023-0036, PYSEC-2023-25 and 4 more.