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.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2021-33580?
The severity of CVE-2021-33580 is high.
What software is affected by CVE-2021-33580?
Apache Roller version up to 6.0.2 is affected by CVE-2021-33580.
How are user-controlled headers used in CVE-2021-33580?
User-controlled headers, such as 'Referer' in the HTTP request, are used to build and run a regex expression.
Can the attacker send a specially crafted Referer header programmatically?
Yes, the attacker can send a specially crafted Referer header programmatically without using a browser.
Are there any references related to CVE-2021-33580?
Yes, you can find references at [this link](http://www.openwall.com/lists/oss-security/2021/08/18/1) and [this link](https://lists.apache.org/thread.html/r9d967d80af941717573e531db2c7353a90bfd0886e9b5d5d79f75506%40%3Cuser.roller.apache.org%3E).