net: validate lwtstate->data before returning from skb_tunnel_info() in Kernel
Summary
GSD-2021-1001439: net: validate lwtstate->data before returning from skb_tunnel_info(). Affects Kernel versions >= 61adedf3e3f1d3f032c5a6a299978d91eff6d555, < b61d327cd3cc5ea591f3bf751dd11e034f388bb5. No fix is published. How to fix ↓
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Background
The Kernel is a crucial component of the Linux operating system that manages the system's resources and facilitates communication between hardware and software. It provides essential functions such as process management, memory management, and device drivers. The vulnerability in question affects the Kernel's networking subsystem.
The skb_tunnel_info() function in the networking subsystem is responsible for retrieving tunnel information from a socket buffer (skb). It is used in various network protocols and features, including tunneling protocols like IPsec and GRE.
The vulnerability arises from a lack of validation of the lwtstate->data field before returning from the skb_tunnel_info() function. This oversight could potentially lead to security issues if an attacker can manipulate the lwtstate->data field to trigger unexpected behavior or exploit memory corruption vulnerabilities.
Vulnerability Detail
The vulnerability lies in the skb_tunnel_info() function within the Kernel's networking subsystem. It arises from the absence of proper validation for the lwtstate->data field before returning from the function. This oversight could allow an attacker to manipulate the lwtstate->data field, potentially leading to security issues such as information disclosure, privilege escalation, or denial of service.
The impact and attack plausibility of this vulnerability have not been proven yet, but it is essential to address it to ensure the security and stability of the affected systems.
The vulnerability was introduced in version v4.3 of the Linux Kernel by commit 61adedf3e3f1d3f032c5a6a299978d91eff6d555. It has been fixed in version v4.9.277 by commit b61d327cd3cc5ea591f3bf751dd11e034f388bb5.
How To Fix
No fixed version is published for this vulnerability.
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Workaround
As a workaround, if updating the Kernel is not immediately feasible, it is recommended to implement additional security measures to mitigate the risk associated with this vulnerability. This may include restricting network access, implementing network segmentation, or employing additional security controls at the network perimeter.
However, applying the official fix by updating the Kernel is the most effective and recommended approach to address the vulnerability.
Conclusion
The vulnerability in the Kernel's networking subsystem, specifically in the skb_tunnel_info() function, poses potential security risks if left unaddressed. It is crucial to update the Linux Kernel to version v4.9.277 or later to apply the necessary fix. Implementing additional security measures as a temporary workaround is also advisable until the update can be applied.
For further support and assistance in vulnerability remediation, please contact DevNack.com.
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FAQ
The impact of this vulnerability could vary depending on the specific system and its configuration. However, potential consequences include information disclosure, privilege escalation, or denial of service.
An attacker could potentially exploit this vulnerability by manipulating the lwtstate->data field in a way that triggers unexpected behavior or exploits memory corruption vulnerabilities. This could lead to security issues such as information disclosure, privilege escalation, or denial of service.
There is no evidence or reports of this vulnerability being exploited in the wild at the time of this disclosure. However, it is crucial to address the vulnerability promptly to mitigate potential risks.
No, not all versions of the Linux Kernel are affected. The vulnerability was introduced in version v4.3 of the Kernel and fixed in version v4.9.277. It is recommended to update to the fixed version or a later release to ensure the vulnerability is addressed.
For more information about this vulnerability, including technical details and the specific commits that introduced and fixed the issue, please refer to the official references provided in the vulnerability report.
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