CVE-2022-27228: Bitrix24 Site Manager RCE Vulnerability

CVE-2022-27228 Overview

CVE-2022-27228 is a critical remote code execution vulnerability affecting the vote (also known as "Polls, Votes") module in Bitrix Site Manager. This vulnerability allows a remote unauthenticated attacker to execute arbitrary code on affected systems. The flaw exists in versions prior to 21.0.100 of the vote module, making it a severe threat to organizations running unpatched Bitrix24 installations.

Critical Impact

Remote unauthenticated attackers can achieve arbitrary code execution on vulnerable Bitrix Site Manager instances, potentially leading to complete system compromise.

Affected Products

• Bitrix24 Bitrix24 (vote module versions before 21.0.100)
• Bitrix Site Manager with vulnerable vote module

Discovery Timeline

• 2022-03-22 - CVE-2022-27228 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2022-27228

Vulnerability Analysis

This vulnerability is classified under CWE-20 (Improper Input Validation), indicating that the vote module fails to properly validate or sanitize user-supplied input before processing. The flaw resides in the "Polls, Votes" functionality of Bitrix Site Manager, which is a component commonly used to gather user feedback and conduct surveys on Bitrix-powered websites.

The vulnerability enables remote code execution without requiring any authentication, meaning attackers can exploit this flaw from anywhere on the internet without needing valid credentials. This makes it particularly dangerous for internet-facing Bitrix installations.

Root Cause

The root cause of CVE-2022-27228 is improper input validation in the vote module of Bitrix Site Manager. The application fails to adequately sanitize or validate user-controlled input, allowing malicious payloads to be processed and ultimately executed on the server. This lack of input validation enables attackers to inject and execute arbitrary code within the context of the web application.

Attack Vector

The attack is network-based and requires no user interaction or prior authentication. An attacker can remotely target vulnerable Bitrix Site Manager installations by sending specially crafted requests to the vote module endpoint. The attack complexity is low, meaning no special conditions or circumstances are required for exploitation. Upon successful exploitation, the attacker gains the ability to execute arbitrary code with the privileges of the web server process, potentially leading to:

• Complete server compromise
• Data exfiltration
• Lateral movement within the network
• Installation of backdoors or malware
• Website defacement

The vulnerability mechanism involves exploiting the vote module's input handling. For specific technical implementation details, refer to the Bitrix24 Helpdesk Article.

Detection Methods for CVE-2022-27228

Indicators of Compromise

• Unusual HTTP requests targeting the vote module endpoints with suspicious payloads
• Unexpected web server child processes or shell commands being executed
• New or modified files in web directories that were not part of legitimate updates
• Anomalous outbound network connections from the web server

Detection Strategies

• Monitor web server access logs for unusual requests to vote module endpoints containing potentially malicious characters or encoded payloads
• Implement web application firewall (WAF) rules to detect and block code injection attempts targeting the vote module
• Deploy file integrity monitoring on Bitrix installation directories to detect unauthorized modifications
• Configure endpoint detection and response (EDR) solutions to alert on suspicious process creation from web server processes

Monitoring Recommendations

• Enable detailed logging for the Bitrix Site Manager application and vote module
• Set up alerts for any code execution patterns originating from web server processes
• Monitor for unusual CPU or memory usage that may indicate malicious activity
• Implement network traffic analysis to detect command and control communications

How to Mitigate CVE-2022-27228

Immediate Actions Required

• Update the Bitrix Site Manager vote module to version 21.0.100 or later immediately
• If immediate patching is not possible, consider temporarily disabling the vote module
• Audit systems for signs of compromise before and after applying patches
• Review web server access logs for evidence of exploitation attempts

Patch Information

Bitrix has addressed this vulnerability in vote module version 21.0.100. Organizations should update to this version or later to remediate the vulnerability. For detailed patching instructions and additional information, consult the Bitrix24 Helpdesk Article.

Workarounds

• Restrict network access to the vote module endpoints using firewall rules or web server configuration
• Implement a web application firewall (WAF) with rules to detect and block code injection attempts
• If the polling functionality is not business-critical, consider disabling the vote module until a patch can be applied
• Use network segmentation to limit the potential impact of a compromised web server

# Example: Restrict access to vote module in Apache (adjust paths as needed)
<Directory "/var/www/bitrix/modules/vote">
    Order deny,allow
    Deny from all
    # Allow only from trusted internal networks
    Allow from 192.168.1.0/24
</Directory>