CVE-2024-22705 in Linux
Summary
by MITRE • 01/23/2024
An issue was discovered in ksmbd in the Linux kernel before 6.6.10. smb2_get_data_area_len in fs/smb/server/smb2misc.c can cause an smb_strndup_from_utf16 out-of-bounds access because the relationship between Name data and CreateContexts data is mishandled.
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Analysis
by VulDB Data Team • 06/06/2025
The vulnerability identified as CVE-2024-22705 resides within the ksmbd implementation in the Linux kernel version prior to 6.6.10, representing a critical security flaw that affects the Server Message Block protocol implementation. This issue manifests in the smb2_get_data_area_len function located in fs/smb/server/smb2misc.c, where improper handling of data relationships between Name and CreateContexts components creates a pathway for out-of-bounds memory access. The ksmbd subsystem serves as a kernel-space SMB server implementation that enables Linux systems to function as SMB/CIFS servers, making this vulnerability particularly dangerous for systems that expose SMB services to external networks. The flaw specifically targets the smb_strndup_from_utf16 function which processes UTF-16 encoded strings during SMB protocol operations, creating potential for memory corruption that could be exploited by remote attackers.
The technical nature of this vulnerability stems from a fundamental flaw in data boundary calculation within the SMB2 protocol processing logic. When handling SMB2_CREATE requests that contain both Name data and CreateContexts data, the kernel fails to properly validate the relationship between these data segments, leading to incorrect memory access patterns. This mismanagement occurs during the parsing of SMB2_CREATE requests where the system attempts to extract and process name information from UTF-16 encoded strings. The improper boundary checking causes the smb_strndup_from_utf16 function to read beyond allocated memory regions, potentially accessing uninitialized memory or memory belonging to other processes. This type of vulnerability falls under the CWE-129 weakness category, specifically addressing improper validation of the length of input data, and represents a classic example of buffer over-read conditions that can lead to information disclosure or arbitrary code execution.
The operational impact of CVE-2024-22705 extends beyond simple memory corruption, as it creates opportunities for remote code execution and system compromise when exploited. Systems running affected kernel versions that expose SMB services to untrusted networks become vulnerable to attacks that could allow adversaries to execute arbitrary code with kernel privileges, potentially leading to complete system takeover. The vulnerability affects any Linux system utilizing ksmbd as its SMB server implementation, including enterprise file servers, NAS devices, and any system configured to provide SMB services. Attackers could exploit this weakness by crafting specially crafted SMB2_CREATE requests that manipulate the Name and CreateContexts data relationships to trigger the out-of-bounds access. This vulnerability aligns with ATT&CK technique T1059.007 for Windows systems, where command execution through kernel-level vulnerabilities can be achieved, though the specific exploitation vector targets Linux kernel space directly.
Mitigation strategies for CVE-2024-22705 primarily focus on immediate kernel version updates to 6.6.10 or later, which contain the necessary patches to address the data boundary handling issue. Organizations should also implement network segmentation to limit access to SMB services, disable unnecessary SMB server functionality, and monitor for suspicious SMB2_CREATE requests that might indicate exploitation attempts. The patch addresses the root cause by implementing proper boundary validation between Name and CreateContexts data segments, ensuring that the smb_strndup_from_utf16 function operates within correctly calculated memory boundaries. Additionally, system administrators should consider implementing network-level firewalls to restrict SMB port access, particularly port 445, and deploy intrusion detection systems that can identify anomalous SMB protocol behavior patterns associated with exploitation attempts. Regular security assessments and kernel version monitoring are essential to maintain protection against similar vulnerabilities in the SMB protocol stack and ensure overall system security posture remains intact.