CVE-2021-33580
regex injection leading to DoS
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
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.
- Record
CVE-2021-33580- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:N/I:N/A:P - Weakness
- CWE-400
- Updated
- 2026-11-02
CVE List No score
regex injection leading to DoS
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.
- Record
CVE-2021-33580- Weakness
- CWE-400
- Updated
- 2026-11-02
EUVDEUVD-2021-20266 No score
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.
- Record
EUVD-2021-20266- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-x9w7-f6x8-r9xh No score
User controlled `request.getHeader("Referer")`, `request.getRequestURL()` and `request...
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.
- Record
GHSA-x9w7-f6x8-r9xh- Weakness
- CWE-400
- Updated
- 2026-11-02
OSV
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.
- Record
CVE-2021-33580- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-33580 is a high vulnerability (CVSS 7.5) in Apache Roller, published August 18, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 3.30%, the 88th percentile. No source names a fixed version.