CVE-2022-50853 in Linux
Summary
by MITRE • 12/30/2025
In the Linux kernel, the following vulnerability has been resolved:
NFSv4: Fix a credential leak in _nfs4_discover_trunking()
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Analysis
by VulDB Data Team • 04/26/2026
The vulnerability identified as CVE-2022-50853 represents a credential leak within the Linux kernel's Network File System version 4 implementation specifically affecting the _nfs4_discover_trunking() function. This issue resides in the core networking subsystem where NFSv4 client operations are handled, making it particularly significant for enterprise environments that rely heavily on networked storage solutions. The flaw manifests during the trunking discovery process which is essential for optimizing NFSv4 communication paths between clients and servers.
The technical root cause of this vulnerability stems from improper handling of security credentials during the trunking discovery phase of NFSv4 operations. When the _nfs4_discover_trunking() function executes, it fails to properly release or clear credential references that are allocated during the discovery process. This credential leak represents a direct violation of the principle of least privilege and can lead to unauthorized access to network resources. The flaw operates at the kernel level where credential management is critical for maintaining system security boundaries and preventing privilege escalation attacks.
From an operational impact perspective, this vulnerability creates potential security risks for systems utilizing NFSv4 networks where attackers could exploit the credential leak to gain unauthorized access to network resources. The leak could allow for prolonged access to shared resources beyond the normal authentication lifetime, potentially enabling data exfiltration, lateral movement, or other malicious activities. Organizations with extensive NFSv4 deployments face increased risk of credential compromise, particularly in environments where network segmentation is not properly implemented. The vulnerability affects systems running Linux kernel versions where the specific NFSv4 implementation is present, making it a widespread concern across enterprise and cloud environments.
Security professionals should prioritize patching this vulnerability as it aligns with CWE-284 (Improper Access Control) and represents a critical weakness in the kernel's credential management system. The flaw could be leveraged by attackers to maintain persistent access to network resources and may provide a foothold for more extensive compromise. Mitigation strategies should include immediate kernel updates, monitoring for unusual network activity related to NFSv4 operations, and implementing additional network segmentation controls. Organizations should also review their NFSv4 configuration and credential handling procedures to minimize potential exploitation opportunities. The vulnerability demonstrates the importance of proper resource cleanup in kernel space and aligns with ATT&CK technique T1078 (Valid Accounts) and T1566 (Phishing) where credential compromise can lead to further exploitation opportunities.