CVE-2021-41387 in seatd
Summary
by MITRE • 09/18/2021
seatd-launch in seatd 0.6.x before 0.6.2 allows privilege escalation because it uses execlp and may be installed setuid root.
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Analysis
by VulDB Data Team • 09/22/2021
The vulnerability identified as CVE-2021-41387 resides within the seatd-launch component of seatd versions 0.6.x prior to 0.6.2, presenting a critical privilege escalation risk that leverages improper execution handling in setuid contexts. This flaw specifically manifests when seatd-launch is installed with root privileges and executes commands using the execlp function, which fails to properly sanitize input parameters before invoking system commands. The issue creates a path for malicious actors to escalate their privileges from a regular user account to root access, fundamentally compromising system security.
The technical implementation of this vulnerability stems from the use of execlp system call within the setuid environment, which does not adequately validate or sanitize command-line arguments passed to the execution function. When seatd-launch processes user input or configuration parameters, it relies on execlp to execute external programs without proper input validation or path sanitization. This creates an environment where an attacker can manipulate input parameters to inject malicious commands that will be executed with root privileges, directly violating the principle of least privilege and allowing unauthorized code execution at the highest system level.
From an operational perspective, this vulnerability represents a severe threat to system integrity as it enables any local user to potentially gain complete system control without requiring additional authentication or exploitation techniques. The impact extends beyond simple privilege escalation to encompass complete system compromise, as the attacker can leverage the elevated privileges to modify system files, install backdoors, or establish persistent access. This vulnerability is particularly concerning in multi-user environments where seatd is used for managing hardware access and user sessions, as it provides a direct path for malicious users to bypass security controls designed to protect system resources.
The vulnerability aligns with CWE-78, which specifically addresses improper neutralization of special elements used in OS commands, and represents a classic example of a command injection flaw in setuid binaries. It also maps to ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation,' demonstrating how an attacker can exploit weaknesses in system components to gain higher-level access rights. The flaw essentially creates a path for arbitrary code execution within a privileged context, making it particularly dangerous for system administrators who rely on seatd for proper hardware access management and user session control.
Mitigation strategies for CVE-2021-41387 require immediate patching of seatd to version 0.6.2 or later, which addresses the improper command execution handling through improved input validation and sanitization. System administrators should also implement additional security controls including monitoring for unauthorized setuid binary modifications, conducting regular security audits of installed packages, and ensuring proper file permissions are maintained on seatd components. The vulnerability underscores the importance of secure coding practices in setuid applications and the necessity of avoiding dangerous system calls like execlp without proper input validation, as recommended by security frameworks such as the OWASP Secure Coding Practices and NIST guidelines for secure software development.