CVE-2023-1537
📋 TL;DR
This vulnerability allows attackers to bypass authentication in the Answer software by capturing and replaying authentication tokens. It affects all Answer deployments running versions prior to 1.0.6, potentially allowing unauthorized access to administrative functions and user data.
💻 Affected Systems
- Answer (answerdev/answer)
📦 What is this software?
Answer by Answer
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise where attackers gain administrative privileges, access all user data, modify system configurations, and potentially execute arbitrary code.
Likely Case
Unauthorized access to administrative functions, data exfiltration, and privilege escalation leading to account takeover and data manipulation.
If Mitigated
Limited impact with proper network segmentation, strong authentication controls, and monitoring in place, though authentication bypass remains possible.
🎯 Exploit Status
Exploitation requires capturing authentication tokens but is straightforward once tokens are obtained.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.0.6 and later
Vendor Advisory: https://github.com/answerdev/answer/commit/813ad0b9894673b1bdd489a2e9ab60a44fe990af
Restart Required: Yes
Instructions:
1. Backup your Answer instance and database. 2. Update to Answer version 1.0.6 or later using your package manager or by downloading from GitHub. 3. Restart the Answer service. 4. Verify the update was successful.
🔧 Temporary Workarounds
Network Segmentation
linuxRestrict network access to Answer instance to trusted IPs only
iptables -A INPUT -p tcp --dport [ANSWER_PORT] -s [TRUSTED_IP] -j ACCEPT
iptables -A INPUT -p tcp --dport [ANSWER_PORT] -j DROP
Rate Limiting
allImplement rate limiting on authentication endpoints to reduce capture opportunities
# Configure in web server (nginx example): limit_req_zone $binary_remote_addr zone=auth:10m rate=10r/m;
# Then apply to auth endpoints
🧯 If You Can't Patch
- Implement strict network access controls to limit exposure
- Enable detailed authentication logging and monitoring for suspicious activity
🔍 How to Verify
Check if Vulnerable:
Check Answer version: if version is less than 1.0.6, system is vulnerableCheck Version:
Check Answer admin panel or run: docker exec [CONTAINER_NAME] answer versionVerify Fix Applied:
Verify Answer version is 1.0.6 or higher and check that authentication tokens now include proper anti-replay protections📡 Detection & Monitoring
Log Indicators:
- Multiple authentication attempts from same token
- Authentication from unusual IP addresses
- Administrative actions from non-admin users
Network Indicators:
- Repeated authentication requests
- Unusual traffic patterns to authentication endpoints
SIEM Query:
source="answer.log" AND ("authentication" OR "login") | stats count by src_ip, user | where count > threshold