CVE-2023-52846 in Linux
Summary
by MITRE • 05/21/2024
In the Linux kernel, the following vulnerability has been resolved:
hsr: Prevent use after free in prp_create_tagged_frame()
The prp_fill_rct() function can fail. In that situation, it frees the skb and returns NULL. Meanwhile on the success path, it returns the original skb. So it's straight forward to fix bug by using the returned value.
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Analysis
by VulDB Data Team • 12/31/2024
The vulnerability identified as CVE-2023-52846 resides within the Linux kernel's HSR (High-availability Seamless Redundancy) implementation, specifically affecting the prp_create_tagged_frame() function. This issue represents a classic use-after-free condition that can potentially lead to system instability or security exploitation. The HSR protocol is designed to provide network redundancy and seamless failover capabilities in industrial networking environments, making this vulnerability particularly concerning for critical infrastructure deployments. The flaw manifests in how the prp_fill_rct() function handles error conditions and resource management, creating a scenario where memory that has been freed can still be accessed by subsequent operations.
The technical root cause of this vulnerability stems from inconsistent return value handling within the HSR subsystem. When prp_fill_rct() encounters an error condition, it properly frees the skb (socket buffer) structure and returns NULL to indicate failure. However, during successful execution paths, the function returns the original skb without proper validation of the return value from prp_fill_rct(). This inconsistency creates a dangerous state where a freed memory reference might be used, leading to memory corruption and potential code execution. The vulnerability falls under CWE-416, which specifically addresses use-after-free conditions, and aligns with ATT&CK technique T1059.001 for command and scripting interpreter usage in exploitation scenarios.
The operational impact of CVE-2023-52846 extends beyond simple system crashes, potentially enabling privilege escalation or denial of service attacks in environments utilizing HSR networking protocols. Systems running Linux kernels with affected HSR implementations are at risk when processing network frames through the prp_create_tagged_frame() function, particularly in industrial control systems, automotive networks, or any environment where HSR redundancy protocols are deployed. The vulnerability's exploitation potential increases in scenarios where attackers can influence network traffic or manipulate the conditions that trigger the prp_fill_rct() error path. Organizations using industrial automation systems, smart grid infrastructure, or real-time network applications that rely on HSR protocols face significant risk from this flaw.
Mitigation strategies for CVE-2023-52846 should prioritize immediate kernel updates from vendors that include the fix for the use-after-free condition. The patch resolves the issue by ensuring proper handling of the return value from prp_fill_rct(), preventing the use of freed memory references. System administrators should also implement network monitoring to detect unusual traffic patterns that might indicate exploitation attempts, particularly in industrial environments where HSR protocols are deployed. Additional defensive measures include network segmentation to limit exposure of affected systems, implementing strict access controls for network management interfaces, and maintaining comprehensive system logging to detect potential exploitation attempts. Organizations should also consider conducting vulnerability assessments focused on industrial control systems to identify other potential weaknesses in their HSR implementations that might compound the risks associated with this particular vulnerability.