CVE-2022-26966 in Linux
Summary
by MITRE • 03/13/2022
An issue was discovered in the Linux kernel before 5.16.12. drivers/net/usb/sr9700.c allows attackers to obtain sensitive information from heap memory via crafted frame lengths from a device.
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Analysis
by VulDB Data Team • 05/18/2025
The vulnerability identified as CVE-2022-26966 represents a critical information disclosure flaw within the Linux kernel's network driver subsystem. This issue affects versions prior to 5.16.12 and specifically targets the sr9700.c driver responsible for handling USB network devices. The vulnerability stems from improper validation of frame lengths received from connected devices, creating a pathway for malicious actors to extract sensitive data from heap memory regions. The flaw demonstrates characteristics consistent with memory corruption vulnerabilities that can be exploited through crafted input manipulation.
The technical implementation of this vulnerability occurs within the USB network driver's frame processing logic where incoming packet lengths are not adequately validated before being used to allocate or access memory buffers. When a malicious device sends frames with crafted lengths that exceed expected boundaries, the driver fails to properly sanitize these inputs, leading to information disclosure from adjacent heap memory locations. This type of vulnerability falls under the CWE-20 category for Improper Input Validation, specifically manifesting as an information exposure through memory access errors. The flaw essentially allows attackers to perform out-of-bounds memory reads that can reveal kernel memory contents including potentially sensitive data such as cryptographic keys, stack contents, or other confidential information.
From an operational impact perspective, this vulnerability poses significant risks to systems running affected Linux kernel versions, particularly those that connect to untrusted USB network devices. Attackers could potentially exploit this flaw to gain insights into kernel memory layout, which could facilitate more sophisticated attacks including privilege escalation or further exploitation techniques. The vulnerability's impact is amplified in environments where USB network devices are frequently connected or where systems handle sensitive data processing. According to ATT&CK framework, this vulnerability could be leveraged as part of a reconnaissance phase (T1069.001 - Credentials in Files) or as a stepping stone for privilege escalation (T1068 - Exploitation for Privilege Escalation) by extracting memory contents that might reveal system internals or credential information.
Mitigation strategies for CVE-2022-26966 primarily involve upgrading to Linux kernel version 5.16.12 or later where the vulnerability has been addressed through proper input validation and memory access controls. System administrators should prioritize patching affected systems and implement network segmentation to limit exposure to untrusted USB devices. Additional defensive measures include monitoring for unusual USB device connections and implementing USB device whitelisting policies where possible. Organizations should also consider deploying kernel hardening techniques such as stack canaries and address space layout randomization to reduce the effectiveness of potential exploitation attempts. The vulnerability highlights the importance of proper input validation in kernel drivers and demonstrates how seemingly benign device communication can become a vector for information disclosure attacks.