CVE-2021-32838 Regular Expression Denial of Service in flask-restx

What is CVE-2021-32838?

CVE-2021-32838 is a high-severity denial of service vulnerability in Fedoraproject Fedora, published on 20 Sep 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Flask-RESTX (pypi package flask-restx) is a community driven fork of Flask-RESTPlus. Flask-RESTX before version 0.5.1 is vulnerable to ReDoS (Regular Expression Denial of Service) in email_regex. This is fixed in version 0.5.1.

Weakness: CWE-400

Which versions are affected by CVE-2021-32838?

3 open source packages ship an affected version, including flask-restx. It affects 2 products.

Products include Fedoraproject Fedora, Flask-Restx Project Flask-Restx.

How do I fix CVE-2021-32838?

Upgrade flask-restx to 0.5.1 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-2021-32838 being exploited?

There is no known exploitation of CVE-2021-32838 in the wild and no public exploit code.

Other vulnerabilities in Fedoraproject Fedora

• CVE-2024-4577 PHP-CGI OS Command Injection Exploited Critical 9.8
• CVE-2021-39226 Grafana Authentication Bypass Exploited Critical 9.8
• CVE-2019-5544 VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow Exploited Critical 9.8
• CVE-2024-4947 Google Chromium V8 Type Confusion Exploited Critical 9.6
• CVE-2024-4671 Google Chromium Visuals Use-After-Free Exploited Critical 9.6

All Fedoraproject Fedora vulnerabilities

Sources

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

Also known as GHSA-3q6g-vf58-7m4g, MGASA-2021-0473, PYSEC-2021-325.