CVE-2024-36935 in Linux
Summary
by MITRE • 05/30/2024
In the Linux kernel, the following vulnerability has been resolved:
ice: ensure the copied buf is NUL terminated
Currently, we allocate a count-sized kernel buffer and copy count bytes from userspace to that buffer. Later, we use sscanf on this buffer but we don't ensure that the string is terminated inside the buffer, this can lead to OOB read when using sscanf. Fix this issue by using memdup_user_nul instead of memdup_user.
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Analysis
by VulDB Data Team • 08/18/2025
The vulnerability identified as CVE-2024-36935 resides within the Linux kernel's ice network driver component, specifically addressing a critical buffer management flaw that could lead to out-of-bounds memory access. This issue affects the Intel Ethernet Connection driver implementation and represents a classic buffer overflow scenario where insufficient null termination of user-supplied data creates potential exploitation vectors. The vulnerability demonstrates a fundamental security gap in kernel space memory handling that directly impacts the integrity and stability of the operating system's networking subsystem.
The technical root cause stems from improper buffer initialization within the kernel's network driver interface where a kernel allocated buffer of size 'count' receives data directly from userspace without ensuring proper null termination of the copied string. When the code subsequently employs sscanf for parsing the buffer content, the absence of null termination can cause the parsing function to read beyond the allocated buffer boundaries, potentially accessing uninitialized memory or adjacent kernel data structures. This flaw specifically manifests when using memdup_user instead of the more secure memdup_user_nul function, which automatically handles null termination of user-provided strings. The vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios, making it particularly dangerous in kernel contexts where memory corruption can lead to privilege escalation.
The operational impact of this vulnerability extends beyond simple memory corruption, potentially enabling attackers to execute arbitrary code with kernel privileges or cause system crashes through controlled memory access violations. Attackers could exploit this weakness by crafting malicious network packets or system calls that trigger the vulnerable code path, leading to information disclosure, system instability, or complete system compromise. The vulnerability affects systems running Linux kernels with the ice driver and presents a significant risk to enterprise networks and cloud environments where kernel-level exploits can provide unauthorized access to critical infrastructure. This issue particularly aligns with ATT&CK technique T1068, which covers local privilege escalation through kernel exploits, and T1566, covering initial access through malicious network traffic.
Mitigation strategies for CVE-2024-36935 involve immediate kernel updates from vendors such as Red Hat, Ubuntu, and other Linux distributions that have released patches addressing this specific buffer management flaw. System administrators should prioritize applying the patched kernel versions as soon as possible, particularly in environments where network access is untrusted or where the affected ice driver is actively used. The fix implemented by the kernel maintainers replaces the insecure memdup_user call with memdup_user_nul, which ensures proper null termination of user-provided data before processing. Additional defensive measures include implementing network segmentation, monitoring for suspicious network activity, and maintaining up-to-date intrusion detection systems that can identify exploitation attempts targeting kernel vulnerabilities. Organizations should also conduct security assessments to identify systems running vulnerable kernel versions and prioritize patching based on risk exposure and criticality of network services.