CVE-2021-33580

Name: CVE-2021-33580
Creator: NVD / NIST
Published: 2021-08-18T08:15:06.173+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 3.30%

Last modified Jun 17, 2026

CVE-2021-33580 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. User controlled `request.getHeader("Referer")`, `request.getRequestURL()` and `request.getQueryString()` are used to build and run a regex expression. The attacker doesn't have to use a browser and may send a specially crafted Referer header programmatically. EPSS estimates a 3.30% chance of exploitation in the next 30 days.

Description

User controlled `request.getHeader("Referer")`, `request.getRequestURL()` and `request.getQueryString()` are used to build and run a regex expression. The attacker doesn't have to use a browser and may send a specially crafted Referer header programmatically. Since the attacker controls the string and the regex pattern he may cause a ReDoS by regex catastrophic backtracking on the server side. This problem has been fixed in Roller 6.0.2.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

3.30%

87.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Apache	Roller	< 6.0.2

References

http://www.openwall.com/lists/oss-security/2021/08/18/1Mailing List, Third Party Advisory
https://lists.apache.org/thread.html/r9d967d80af941717573e531db2c7353a90bfd0886e9b5d5d79f75506%40%3Cuser.roller.apache.org%3EMailing List, Vendor Advisory
http://www.openwall.com/lists/oss-security/2021/08/18/1Mailing List, Third Party Advisory
https://lists.apache.org/thread.html/r9d967d80af941717573e531db2c7353a90bfd0886e9b5d5d79f75506%40%3Cuser.roller.apache.org%3EMailing List, Vendor Advisory

Timeline

Published: Aug 18, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-33580?

How severe is CVE-2021-33580?

CVE-2021-33580 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 3.30% probability of exploitation in the next 30 days.

How do I fix CVE-2021-33580?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-33580?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST