CVE-2021-39686 is a high-severity vulnerability affecting the Android kernel. This vulnerability allows a potential way to represent the wrong domain to SELinux, stemming from a race condition in several functions of binder.c. As a result, this could lead to local privilege escalation without requiring additional execution privileges. Notably, user interaction is not necessary for exploitation, which increases the risk to systems running vulnerable versions.
The CVSS score for this vulnerability is 7, classified as high severity. The implications of such a score indicate that the vulnerability can be exploited locally, with a high attack complexity, yet low privileges are required for exploitation. Attackers could potentially gain significant control over affected systems, impacting confidentiality, integrity, and availability.
Organizations should prioritize patching immediately to mitigate the risks associated with this vulnerability. The urgency stems from its high impact potential and the fact that it does not require user interaction for exploitation, making it a critical concern for security teams.
As of the latest information, there are no known public exploits or proofs of concept available for CVE-2021-39686, but the lack of these should not diminish the importance of addressing this vulnerability swiftly.
Vulnerability Details
The official description of this vulnerability states that it arises from a potential race condition in several functions of binder.c, which could allow the wrong domain representation to SELinux. This situation creates an opportunity for local privilege escalation without additional execution privileges required. The affected product is the Android kernel, and this vulnerability was first published on March 16, 2022.
The CVSS score for this vulnerability is classified as high, with a base score of 7. This score reflects the vulnerability's ability to impact confidentiality, integrity, and availability at a high level. It is further categorized under CWE-362, indicating a race condition vulnerability.
Technical Analysis
The root cause of CVE-2021-39686 is a race condition in the Android kernel's binder.c file, which may lead to incorrect domain representation for SELinux. This issue arises when concurrent processes attempt to access shared resources without proper synchronization, resulting in an inconsistent state that can be exploited.
The attack vector for this vulnerability is local, requiring the attacker to have access to the system. The attack complexity is considered high due to the necessary conditions for exploiting the race condition effectively. Privileges required for exploitation are low, meaning that users with minimal access can potentially escalate their privileges.
User interaction is not required for exploitation, which further emphasizes the severity of the vulnerability. Should an attacker successfully exploit this vulnerability, they could achieve high impacts on confidentiality, integrity, and availability, effectively compromising the system.
Risk & Impact Analysis
Risk to organizations includes the potential for unauthorized access and control over devices running affected versions of the Android kernel. Given the nature of the vulnerability, any successful exploitation could lead to severe data breaches and compromises of sensitive information.
The blast radius for this vulnerability is considerable, as it affects all versions prior to the vendor patch. Organizations using Android devices across various sectors must take immediate action to apply the necessary patches to safeguard against potential exploitation.
Given the high CVSS score and the absence of known public exploits, organizations should still treat this vulnerability with urgency, addressing it in their priority patch cycle. The risk of privilege escalation and subsequent unauthorized access underscores the critical nature of this vulnerability.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
All versions of the Android kernel prior to the vendor patch are affected by this vulnerability. Organizations should verify their systems and ensure they are running the latest patched versions to mitigate risks.
Mitigation & Remediation
To remediate this vulnerability, organizations should apply the latest patches provided by Google. Keeping systems updated will mitigate the risk of exploitation. In cases where immediate patching is not possible, organizations may consider implementing configuration hardening measures and monitoring for unusual activities.
For more information, organizations can refer to the penetration testing services offered by AppSecure to evaluate their security posture.
Detection Guidance
Organizations should monitor logs for indicators of exploitation attempts related to this vulnerability. Behavioral anomalies and changes in system performance could signal attempts to exploit the race condition. Additionally, network signatures that deviate from normal patterns should be investigated.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2021-39686 highlights the importance of rigorous testing in the development of critical software components like the Android kernel. This vulnerability serves as a reminder of the potential risks posed by race conditions, which can lead to serious security breaches if not properly managed.
Organizations should adopt a proactive stance by conducting regular security assessments and ensuring their defenses are robust against emerging threats. For further insights, security teams can explore our guide on vulnerability management programs and the importance of timely patching.
Finally, organizations should also consider engaging in penetration testing to assess their vulnerabilities and improve their security posture.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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