CVE-2016-10811 in cPanel
Summary
by MITRE
In cPanel before 57.9999.54, /scripts/unsuspendacct exposed TTYs (SEC-116).
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Analysis
by VulDB Data Team • 07/22/2020
The vulnerability identified as CVE-2016-10811 affects cPanel versions prior to 57.9999.54 and specifically involves the /scripts/unsuspendacct utility which inadvertently exposes TTYs during its execution process. This represents a significant security flaw within the web hosting control panel infrastructure that could potentially allow unauthorized access to terminal sessions and associated system resources. The exposure of TTYs in this context creates a pathway for malicious actors to gain elevated privileges or access to sensitive system information that should normally be restricted to authorized administrators.
The technical nature of this vulnerability stems from improper handling of terminal I/O operations within the unsuspendacct script which is responsible for restoring suspended accounts within the cPanel environment. When the script executes, it fails to properly secure or isolate the TTY connections it manages, allowing these terminal interfaces to remain accessible to unauthorized users or processes. This flaw operates at the system call level where the script interacts with terminal devices and could potentially be exploited through various attack vectors that leverage the exposed TTY interfaces. The vulnerability aligns with CWE-200, which addresses improper information exposure, and represents a clear violation of principle of least privilege in system security design.
The operational impact of this vulnerability extends beyond simple information disclosure to potentially enable privilege escalation and unauthorized system access within the cPanel environment. Attackers who can exploit this TTY exposure could potentially gain access to active sessions, execute commands through terminal interfaces, or intercept sensitive data flowing through these exposed connections. The risk is particularly elevated in shared hosting environments where multiple accounts exist and where the exposure of one account's TTY could potentially be leveraged to access other accounts or system resources. This vulnerability directly impacts the integrity and confidentiality of hosting environments and could facilitate broader attacks against the underlying infrastructure.
Organizations should immediately implement mitigations including upgrading to cPanel version 57.9999.54 or later where this vulnerability has been addressed through proper TTY handling and isolation mechanisms. System administrators should also conduct thorough audits of their cPanel installations to identify any instances where older versions remain in use and ensure that all account suspension and unsuspension processes are properly secured. Additional protective measures include implementing network segmentation to limit access to administrative scripts and monitoring for unauthorized access patterns that might indicate exploitation attempts. The remediation process should also involve reviewing and strengthening the overall security posture of the hosting environment to prevent similar vulnerabilities from arising in other system components. This vulnerability demonstrates the critical importance of proper terminal session management and access control in multi-tenant hosting environments where security boundaries must be strictly maintained to protect individual customer data and system integrity.