CVE-2024-39524
📋 TL;DR
This CVE describes a local privilege escalation vulnerability in Juniper Junos OS Evolved where authenticated low-privilege users can execute specific CLI commands with crafted parameters to gain root access. The vulnerability affects multiple Junos OS Evolved versions due to improper handling of command options. Attackers with local access can fully compromise affected systems.
💻 Affected Systems
- Juniper Networks Junos OS Evolved
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with root access, allowing complete control over network devices, data exfiltration, and persistence establishment.
Likely Case
Privileged attackers gaining root access to manipulate network configurations, intercept traffic, or deploy additional malware.
If Mitigated
Limited impact if proper access controls restrict local user access and command execution capabilities.
🎯 Exploit Status
Exploitation requires authenticated access and knowledge of vulnerable commands
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 20.4R3-S7-EVO, 21.2R3-S8-EVO, 21.4R3-S7-EVO, 22.2R3-EVO, 22.3R2-EVO, 22.4R2-EVO or later
Vendor Advisory: https://supportportal.juniper.net/JSA82975
Restart Required: Yes
Instructions:
1. Download appropriate patched version from Juniper support portal. 2. Backup current configuration. 3. Install update following Juniper upgrade procedures. 4. Reboot device. 5. Verify version and functionality.
🔧 Temporary Workarounds
Restrict CLI command access
allLimit which users can execute CLI commands through Junos OS role-based access control
set system login class restricted permissions [configured-permissions]
Monitor command execution
allEnable auditing of CLI command execution to detect suspicious activity
set system syslog file commands any any
set system syslog file commands archive size 10m
🧯 If You Can't Patch
- Implement strict access controls to limit local user access to CLI commands
- Monitor for unusual privilege escalation attempts and command execution patterns
🔍 How to Verify
Check if Vulnerable:
Check Junos OS Evolved version with: show version | match JunosCheck Version:
show version | match JunosVerify Fix Applied:
Verify version is patched: show version | match Junos and confirm version is 20.4R3-S7-EVO, 21.2R3-S8-EVO, 21.4R3-S7-EVO, 22.2R3-EVO, 22.3R2-EVO, 22.4R2-EVO or later📡 Detection & Monitoring
Log Indicators:
- Unusual CLI command execution patterns
- Privilege escalation attempts
- Root access from non-admin users
Network Indicators:
- Configuration changes from unexpected sources
- Unauthorized network modifications
SIEM Query:
source="junos" AND (event_type="command_execution" AND user!="admin") OR (privilege="root" AND user!="root")