CVE-2013-4335
📋 TL;DR
This vulnerability allows attackers to perform XML External Entity (XXE) injection attacks in opOpenSocialPlugin, potentially leading to sensitive data disclosure, server-side request forgery, or denial of service. It affects opOpenSocialPlugin versions 0.8.2.1, > 0.9.9.2, 0.9.13, and 1.2.6. Organizations using these vulnerable versions are at risk.
💻 Affected Systems
- opOpenSocialPlugin
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise including arbitrary file read, internal network reconnaissance, and potential remote code execution via XXE attacks.
Likely Case
Sensitive data disclosure (configuration files, credentials) and server-side request forgery to internal systems.
If Mitigated
Limited impact if XML parsing is disabled or external entity processing is restricted.
🎯 Exploit Status
XXE vulnerabilities are well-understood with public exploit techniques available. The high CVSS score suggests trivial exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after the affected releases (check specific advisory for exact fixed version)
Vendor Advisory: http://www.openwall.com/lists/oss-security/2013/09/11/6
Restart Required: Yes
Instructions:
1. Identify current opOpenSocialPlugin version. 2. Upgrade to a version that addresses CVE-2013-4335. 3. Restart the application/service. 4. Verify the fix is applied.
🔧 Temporary Workarounds
Disable External Entity Processing
allConfigure XML parser to disable external entity resolution
Set XML parser properties: FEATURE_SECURE_PROCESSING=true, DISALLOW_DOCTYPE_DECL=true
Input Validation Filter
allImplement input filtering to reject XML containing external entity declarations
Implement regex filter: /<!ENTITY\s+\S+\s+SYSTEM\s+['"][^'"]+['"]>/i
🧯 If You Can't Patch
- Network segmentation: Isolate affected systems from sensitive internal networks
- Implement WAF rules to block XXE payloads at the perimeter
🔍 How to Verify
Check if Vulnerable:
Check opOpenSocialPlugin version against affected versions list. Test with XXE payload: <?xml version="1.0"?><!DOCTYPE test [<!ENTITY xxe SYSTEM "file:///etc/passwd">]><test>&xxe;</test>Check Version:
Check plugin configuration files or application logs for opOpenSocialPlugin versionVerify Fix Applied:
After patching, retest with XXE payloads. Verify XML parser configuration disallows external entities.📡 Detection & Monitoring
Log Indicators:
- XML parsing errors with external entity references
- Unexpected file read attempts in logs
- HTTP requests containing XML with DOCTYPE declarations
Network Indicators:
- HTTP POST/PUT requests with XML content containing external entity declarations
- Outbound connections from server to internal systems triggered by XML parsing
SIEM Query:
http.method:(POST OR PUT) AND http.content_type:application/xml AND http.request_body:*ENTITY*SYSTEM*🔗 References
- http://www.openwall.com/lists/oss-security/2013/09/11/6
- http://www.securityfocus.com/bid/62287
- https://exchange.xforce.ibmcloud.com/vulnerabilities/87033
- http://www.openwall.com/lists/oss-security/2013/09/11/6
- http://www.securityfocus.com/bid/62287
- https://exchange.xforce.ibmcloud.com/vulnerabilities/87033
