CVE-2023-0461 is a high-severity vulnerability affecting the Linux Kernel, classified as a use-after-free issue. This vulnerability allows attackers to achieve local privilege escalation under specific kernel configurations, particularly when the CONFIG_TLS or CONFIG_XFRM_ESPINTCP flags are enabled. The exploitation of this vulnerability does not require elevated privileges, increasing the risk for organizations using affected versions.
The vulnerability arises from a use-after-free bug in the icsk_ulp_data structure of a struct inet_connection_sock. When CONFIG_TLS is enabled and a TLS context is installed on a connected TCP socket, the context is not cleared if the socket is disconnected and then reused as a listener. Consequently, if a new socket is created from this listener, it inherits the vulnerable context, creating an attack vector.
Risk to organizations includes unauthorized access and potential escalation of privileges for local attackers, which could lead to significant system compromise. Given the vulnerability's high CVSS score of 7.8 and its potential impact on confidentiality, integrity, and availability, organizations should prioritize patching immediately.
Currently, there are no public exploits confirmed for this vulnerability, but the existence of potential exploitation vectors necessitates immediate attention from security teams to mitigate risks effectively.
Vulnerability Details
CVE-2023-0461 is characterized as a use-after-free vulnerability, which can be exploited for local privilege escalation. The official description indicates that the vulnerability is present in the Linux Kernel when specific configurations, such as CONFIG_TLS or CONFIG_XFRM_ESPINTCP, are enabled. The CVSS score is 7.8, categorizing it as a high-severity issue.
The vulnerability was published on February 28, 2023, and is classified under CWE-416, which refers to use-after-free vulnerabilities. It affects all versions of the Linux Kernel from 4.13.0 up to but not including 4.14.303, and similarly for versions 4.19, 5.4, 5.10, 5.15, 6.0, and 6.1, with specific ranges detailed in the configurations.
Technical Analysis
The root cause of CVE-2023-0461 is the use-after-free condition resulting from improper handling of TLS contexts in the Linux Kernel. The attack vector is local, meaning it requires local access to the vulnerable system for exploitation. The attack complexity is low, as the necessary conditions for exploitation do not require special privileges or user interactions.
The required privileges are low, allowing any user with access to the system to exploit the vulnerability. There is no user interaction required for the attack to succeed. The impacts of successful exploitation include high confidentiality, integrity, and availability impacts, making it a significant threat to system security.
Risk & Impact Analysis
The real-world deployment risk stemming from CVE-2023-0461 is considerable. Organizations running affected versions of the Linux Kernel are at a heightened risk of local privilege escalation, which could lead to unauthorized access to sensitive data and critical system components. The potential blast radius includes all systems utilizing the vulnerable kernel configurations, necessitating a prompt response.
The urgency for organizations to address this vulnerability is reinforced by its CVSS score of 7.8 and the absence of known exploits. Organizations should address this vulnerability in their priority patch cycle to mitigate risks before they escalate.
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | Yes |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The vulnerability affects all versions of the Linux Kernel starting from 4.13.0 up to but not including 4.14.303, as well as various other ranges, including 4.19, 5.4, 5.10, 5.15, 6.0, and 6.1. Specifically, the vulnerability is also present in the 6.2 release candidates.
Mitigation & Remediation
Organizations should prioritize upgrading their Linux Kernel to a version beyond commit 2c02d41d71f90a5168391b6a5f2954112ba2307c to mitigate this vulnerability. If patching is not immediately feasible, organizations should implement strict access controls and monitor logs for unusual activities that may indicate attempts to exploit this vulnerability.
Detection Guidance
Organizations should monitor system logs for indicators of exploitation attempts related to this vulnerability. This includes unusual socket behavior or error messages associated with TCP connections. Additionally, logging and analyzing setsockopt operations may provide insight into potential abuse of the TCP_ULP operation.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2023-0461 lies in its demonstration of how local privilege escalation vulnerabilities can be exploited without requiring high privileges. This case underscores the importance of thorough security practices in kernel development and the necessity for ongoing vigilance in monitoring kernel configurations.
Security teams should learn from this vulnerability and ensure that TLS contexts are properly managed to prevent similar exploitations in the future. Regular audits of kernel configurations and timely patching should become a standard practice to safeguard against such vulnerabilities.
For further insights into managing vulnerabilities, organizations can refer to resources on vulnerability management programs and consider implementing penetration testing to evaluate 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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