CVE-2022-0982
📋 TL;DR
CVE-2022-0982 is a critical memory corruption vulnerability in accel-pppd's telnet component that allows remote attackers to execute arbitrary code or crash the service. The vulnerability affects systems running accel-pppd with telnet enabled. Attackers can exploit this without authentication by sending specially crafted telnet requests.
💻 Affected Systems
- accel-pppd
📦 What is this software?
Accel Ppp by Accel Ppp
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with root privileges leading to complete system compromise, data theft, and persistent backdoor installation.
Likely Case
Service crash causing denial of service and potential remote code execution with the privileges of the accel-pppd process.
If Mitigated
Limited impact if telnet is disabled or network access is restricted, potentially only causing service disruption.
🎯 Exploit Status
The vulnerability is straightforward to exploit due to lack of bounds checking on user input.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not specified in references, but fix is available in GitHub repository
Vendor Advisory: https://github.com/xebd/accel-ppp/issues/164
Restart Required: Yes
Instructions:
1. Update accel-pppd to the latest version from the official repository. 2. Restart the accel-pppd service. 3. Verify the fix is applied.
🔧 Temporary Workarounds
Disable telnet functionality
linuxDisable telnet access in accel-pppd configuration to prevent exploitation
Edit accel-pppd configuration file and remove or comment out telnet-related settings
Restart accel-pppd service
Network access control
linuxRestrict network access to accel-pppd telnet port (default 23) using firewall rules
iptables -A INPUT -p tcp --dport 23 -j DROP
ufw deny 23/tcp
🧯 If You Can't Patch
- Disable telnet functionality in accel-pppd configuration immediately
- Implement strict network segmentation and firewall rules to block all telnet access to affected systems
🔍 How to Verify
Check if Vulnerable:
Check if accel-pppd is running with telnet enabled and version is not patchedCheck Version:
accel-pppd --version or check package manager (apt list --installed | grep accel-pppd)Verify Fix Applied:
Verify accel-pppd version is updated and telnet functionality is either disabled or patched📡 Detection & Monitoring
Log Indicators:
- Unusual telnet connection attempts
- accel-pppd crash logs
- Memory corruption errors in system logs
Network Indicators:
- Unexpected telnet traffic to accel-pppd ports
- Malformed telnet packets
SIEM Query:
source="accel-pppd" AND (event="crash" OR event="segmentation fault") OR destination_port=23 AND protocol="telnet"