CVE-2023-53008 in Linux
Summary
by MITRE • 03/27/2025
In the Linux kernel, the following vulnerability has been resolved:
cifs: fix potential memory leaks in session setup
Make sure to free cifs_ses::auth_key.response before allocating it as we might end up leaking memory in reconnect or mounting.
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Analysis
by VulDB Data Team • 12/07/2025
The vulnerability identified as CVE-2023-53008 resides within the Linux kernel's Common Internet File System (CIFS) implementation, specifically addressing a critical memory management flaw in the session setup process. This issue manifests as a potential memory leak that can occur during CIFS session reconnection or mounting operations, representing a significant concern for systems relying on network file sharing protocols. The vulnerability impacts the cifs_ses structure's auth_key.response field, where improper memory handling can lead to resource exhaustion over time.
The technical flaw stems from insufficient memory cleanup procedures within the CIFS session management code. When the kernel attempts to reallocate memory for the auth_key.response field during session reconnection or mounting processes, it fails to properly free the previously allocated memory before performing new allocations. This creates a memory leak scenario where old memory allocations remain unreleased, gradually consuming system resources. The issue is particularly dangerous in environments where CIFS sessions are frequently established and torn down, as the cumulative effect of these leaks can lead to system instability or performance degradation.
From an operational perspective, this vulnerability poses substantial risks to enterprise environments that heavily utilize CIFS-based file sharing services. Systems experiencing frequent session reconnects or mounting operations may suffer from progressive memory consumption, potentially leading to system crashes, reduced performance, or denial of service conditions. The memory leaks can compound over time, especially in high-availability environments where CIFS services are continuously accessed and reconnected, making this a critical concern for infrastructure stability and resource management.
The mitigation strategy involves implementing proper memory management practices within the CIFS subsystem to ensure that cifs_ses::auth_key.response memory is freed before new allocations occur. This aligns with established security principles and follows the CWE-401: Improper Release of Memory Before Next Refusal pattern, which specifically addresses memory leak vulnerabilities. Organizations should prioritize applying the kernel patches that resolve this issue, as the vulnerability can be exploited to consume system resources over time, potentially leading to system instability. The fix ensures that memory cleanup occurs before new allocations, preventing the accumulation of unreleased memory blocks that characterize this type of vulnerability. This remediation approach directly addresses the ATT&CK technique T1499.004: Endpoint Denial of Service by ensuring proper resource management in network file system operations.