CVE-2025-34030: sar2html RCE Vulnerability

CVE-2025-34030 Overview

CVE-2025-34030 is a critical OS command injection vulnerability affecting sar2html version 3.2.2 and prior versions. The vulnerability exists in the plot parameter within index.php, where the application fails to sanitize user-supplied input before using it in a system-level context. Remote, unauthenticated attackers can inject arbitrary shell commands by appending them to the plot parameter (e.g., ?plot=;id) in a crafted GET request. The output of the injected command is displayed in the application's interface after interacting with the host selection UI, enabling full command execution on the underlying system.

Critical Impact

This vulnerability allows unauthenticated remote attackers to execute arbitrary operating system commands on the underlying server, potentially leading to complete system compromise, data exfiltration, and lateral movement within the network.

Affected Products

• sar2html version 3.2.2
• sar2html versions prior to 3.2.2
• Web servers hosting vulnerable sar2html installations

Discovery Timeline

• 2025-02-04 - Exploitation evidence observed by the Shadowserver Foundation
• 2025-06-20 - CVE CVE-2025-34030 published to NVD
• 2025-11-20 - Last updated in NVD database

Technical Details for CVE-2025-34030

Vulnerability Analysis

This command injection vulnerability (CWE-78) stems from improper input validation in the sar2html web application. The plot parameter in index.php accepts user input that is subsequently passed to system-level functions without adequate sanitization. Because the application directly incorporates user-controlled data into operating system commands, attackers can break out of the intended command context using shell metacharacters such as semicolons (;), pipes (|), or command substitution operators.

The attack is particularly dangerous because it requires no authentication, operates over the network, and provides direct feedback to the attacker through the web interface. The vulnerability has been documented with exploitation evidence in the wild, indicating active threat actor interest.

Root Cause

The root cause is the failure to implement proper input validation and sanitization on the plot parameter before it is used in a system command execution context. The application directly concatenates or interpolates user input into shell commands without escaping special characters or using parameterized command execution methods. This design flaw allows attackers to inject additional commands that execute with the privileges of the web server process.

Attack Vector

The attack is conducted remotely over the network via HTTP GET requests. An attacker crafts a malicious URL targeting the index.php endpoint with a manipulated plot parameter containing shell metacharacters followed by arbitrary commands. For example, appending ;id to the parameter value causes the id command to execute on the server. More sophisticated payloads can establish reverse shells, download additional malware, or exfiltrate sensitive data.

The exploitation flow involves:

1. Sending a crafted GET request with command injection payload in the plot parameter
2. The web application processes the request and passes unsanitized input to a system function
3. The injected command executes with web server process privileges
4. Command output is returned through the application's host selection interface

Exploitation details and proof-of-concept code are available in the Exploit-DB #47204 and the VulnCheck Security Advisory.

Detection Methods for CVE-2025-34030

Indicators of Compromise

• HTTP GET requests to /index.php containing shell metacharacters (;, |, &, `, $()) in the plot parameter
• Unusual process spawning from the web server process (e.g., sh, bash, wget, curl, nc, python)
• Outbound network connections from the web server to unknown external IP addresses
• Web server error logs showing command execution failures or unexpected system calls
• File system modifications in web-accessible directories or unusual files in /tmp

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect and block command injection patterns in the plot parameter
• Implement intrusion detection system (IDS) signatures for sar2html exploitation attempts matching known payload patterns
• Monitor web server access logs for requests containing encoded or unencoded shell metacharacters targeting index.php
• Configure endpoint detection to alert on suspicious child process creation from web server parent processes

Monitoring Recommendations

• Enable verbose logging on web servers hosting sar2html and forward logs to SIEM for analysis
• Implement network traffic analysis to detect command-and-control communications following potential exploitation
• Set up file integrity monitoring on sar2html installation directories and system binaries
• Monitor for privilege escalation attempts or unusual user account creation following web server compromise

How to Mitigate CVE-2025-34030

Immediate Actions Required

• Remove or disable sar2html installations from production environments if not actively required
• Implement network segmentation to isolate systems running sar2html from critical infrastructure
• Deploy WAF rules to block requests containing shell metacharacters in the plot parameter
• Restrict access to sar2html to authorized internal IP ranges only via firewall rules
• Audit systems for indicators of compromise if sar2html has been exposed to the internet

Patch Information

As of the last NVD update on 2025-11-20, organizations should consult the sar2html GitHub repository for the latest version information and any available security patches. Given the severity of this vulnerability, consider replacing sar2html with alternative SAR data visualization tools that have active security maintenance.

Additional technical guidance is available from the FortiGuard IPS Encyclopedia Entry for implementing network-based protections.

Workarounds

• Disable the vulnerable plot parameter functionality by modifying index.php to reject requests containing this parameter
• Implement server-side input validation that strictly allowlists alphanumeric characters for the plot parameter
• Run sar2html in a containerized or sandboxed environment with minimal system privileges
• Place sar2html behind an authenticated reverse proxy to prevent unauthenticated access

# Example: Apache configuration to restrict access to sar2html
<Directory /var/www/sar2html>
    # Deny all access by default
    Require all denied
    # Allow only from trusted internal network
    Require ip 10.0.0.0/8
    Require ip 192.168.0.0/16
</Directory>

# Example: Block requests with shell metacharacters using mod_security
SecRule ARGS:plot "@rx [;|&\`$()]" "id:100001,phase:2,deny,status:403,msg:'Potential command injection in plot parameter'"