CVE-2021-32816

Public Exploit
Regular expression Denial of Service in ProtonMail

Description

ProtonMail Web Client is the official AngularJS web client for the ProtonMail secure email service. ProtonMail Web Client before version 3.16.60 has a regular expression denial-of-service vulnerability. This was fixed in commit 6687fb. There is a full report available in the referenced GHSL-2021-027.

Category

6.5
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.29%
Third-Party Advisory github.com Third-Party Advisory github.com
Affected: ProtonMail WebClient
Published at:
Updated at:

References

Link Tags
https://securitylab.github.com/advisories/GHSL-2021-027-redos-ProtonMail/ third party advisory exploit
https://github.com/ProtonMail/WebClient/commit/6687fbb867ef872c96cf4fde68cb6e9c58d3fddc third party advisory patch

Frequently Asked Questions

What is the severity of CVE-2021-32816?
CVE-2021-32816 has been scored as a medium severity vulnerability.
How to fix CVE-2021-32816?
To fix CVE-2021-32816, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-32816 being actively exploited in the wild?
It is possible that CVE-2021-32816 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-32816?
CVE-2021-32816 affects ProtonMail WebClient.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.