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How the CVE Works
The vulnerability (CVE-2025-XXXX) in Apache Tomcat arises from improper neutralization of escape sequences in rewrite rules. Attackers can craft malicious HTTP requests containing specially formatted escape or control sequences that bypass security constraints enforced by rewrite rules. This affects configurations where rewrite rules act as security filters (e.g., blocking unauthorized paths). The flaw occurs due to insufficient input sanitization before processing rewrite conditions, allowing attackers to evade restrictions by manipulating request sequences.
DailyCVE Form:
Platform: Apache Tomcat
Version: 9.0.76-9.0.102
Vulnerability: Rewrite bypass
Severity: Low
Date: Apr 28, 2025
What Undercode Say:
Exploitation:
1. Craft Malicious Request:
curl -H "Escape-Sequence: \x1b" "http://target:8080/restricted/%5Cx2fbypass"
2. Bypass Rewrite Rules:
- Use URL-encoded meta-characters (
%0A,%0D) to disrupt rule parsing. - Example exploit path:
/restricted/%0A../admin.
Detection:
1. Log Analysis:
grep -E "%0A|%0D|%5C" /var/log/tomcat/localhost_access.log
2. Rule Testing:
python3 -c "import requests; print(requests.get('http://target:8080/%0Aadmin').status_code)"
Mitigation:
1. Patch Upgrade:
wget https://tomcat.apache.org/download-90.cgi -O tomcat-patched.tar.gz
2. Input Sanitization:
<Valve className="org.apache.catalina.valves.RewriteValve" allowedEscapeSequences="false"/>
3. Rule Hardening:
RewriteRule ^restricted/. - [bash] Force deny malformed sequences
Analytics:
- Affected Systems: Tomcat 9.x (9.0.76-9.0.102), 10.x (10.1.10-10.1.39).
- Exploit Complexity: Low (requires specific rewrite configurations).
- CVSS Score: 3.5 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N).
References:
Sources:
Reported By: github.com
Extra Source Hub:
Undercode
