CVE-2023-29489 in cPanel
Summary
by MITRE • 04/28/2023
An issue was discovered in cPanel before 11.109.9999.116. XSS can occur on the cpsrvd error page via an invalid webcall ID, aka SEC-669. The fixed versions are 11.109.9999.116, 11.108.0.13, 11.106.0.18, and 11.102.0.31.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 05/21/2023
The vulnerability CVE-2023-29489 represents a cross-site scripting flaw within the cPanel web hosting control panel software that affects versions prior to 11.109.9999.116. This security issue resides in the cpsrvd service which handles web requests and error reporting within the cPanel environment. The vulnerability specifically manifests when the system encounters an invalid webcall ID parameter, which is a critical component in the communication protocol between the client and the server. This flaw allows attackers to inject malicious scripts into error pages that are displayed to users, creating a persistent vector for exploitation.
The technical implementation of this vulnerability stems from inadequate input validation and sanitization within the error handling mechanism of cPanel's cpsrvd process. When an invalid webcall ID is submitted to the system, the error page generation process fails to properly escape or filter user-supplied input before rendering it in the browser context. This lack of proper sanitization creates a classic cross-site scripting condition where malicious payloads can be executed in the context of a victim's browser session. The vulnerability is categorized under CWE-79 - Improper Neutralization of Input During Web Page Generation, which specifically addresses the failure to neutralize output that is intended for web browsers.
The operational impact of this vulnerability extends beyond simple script execution as it provides attackers with the capability to hijack user sessions, steal sensitive authentication tokens, and potentially escalate privileges within the compromised cPanel environment. An attacker could craft malicious webcall ID parameters that, when processed by the vulnerable error page, would execute scripts in the victim's browser. This could lead to unauthorized access to customer accounts, data exfiltration, and potential compromise of the entire hosting environment. The vulnerability is particularly concerning because cPanel serves as a critical management interface for web hosting providers, making it an attractive target for attackers seeking to gain unauthorized access to multiple customer accounts simultaneously.
Security professionals should note that this vulnerability aligns with ATT&CK technique T1566.001 - Phishing: Spearphishing Attachment, as it could be exploited through crafted webcall ID parameters delivered via phishing campaigns or other social engineering methods. The remediation process requires immediate deployment of the patched versions 11.109.9999.116, 11.108.0.13, 11.106.0.18, and 11.102.0.31, which implement proper input sanitization and output encoding mechanisms. Organizations should also consider implementing additional security controls such as web application firewalls, input validation rules, and regular security audits of their cPanel installations to prevent similar vulnerabilities from emerging in other components of their hosting infrastructure. The patch addresses the root cause by ensuring that all user-supplied parameters are properly validated and escaped before being rendered in error page contexts, thereby eliminating the XSS vector entirely.