CVE-2024-49997

In the Linux kernel, the following vulnerability has been resolved:

net: ethernet: lantiq_etop: fix memory disclosure

When applying padding, the buffer is not zeroed, which results in memory disclosure. The mentioned data is observed on the wire. This patch uses skb_put_padto() to pad Ethernet frames properly. The mentioned function zeroes the expanded buffer.

In case the packet cannot be padded it is silently dropped. Statistics are also not incremented. This driver does not support statistics in the old 32-bit format or the new 64-bit format. These will be added in the future. In its current form, the patch should be easily backported to stable versions.

Ethernet MACs on Amazon-SE and Danube cannot do padding of the packets in hardware, so software padding must be applied.

Weakness

The product stores, transfers, or shares a resource that contains sensitive information, but it does not properly remove that information before the product makes the resource available to unauthorized actors.

Affected Software

Extended Description

Resources that may contain sensitive data include documents, packets, messages, databases, etc. While this data may be useful to an individual user or small set of users who share the resource, it may need to be removed before the resource can be shared outside of the trusted group. The process of removal is sometimes called cleansing or scrubbing. For example, a product for editing documents might not remove sensitive data such as reviewer comments or the local pathname where the document is stored. Or, a proxy might not remove an internal IP address from headers before making an outgoing request to an Internet site.

Potential Mitigations

• Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
• Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/168.html

References

• https://git.kernel.org/stable/c/1097bf16501ed5e35358d848b0a94ad2830b0f65
• https://git.kernel.org/stable/c/185df159843d30fb71f821e7ea4368c2a3bfcd36
• https://git.kernel.org/stable/c/2bf4c101d7c99483b8b15a0c8f881e3f399f7e18
• https://git.kernel.org/stable/c/431b122933b197820d319eb3987a67d04346ce9e
• https://git.kernel.org/stable/c/45c0de18ff2dc9af01236380404bbd6a46502c69
• https://git.kernel.org/stable/c/469856f76f4802c5d7e3d20e343185188de1e2db
• https://git.kernel.org/stable/c/60c068444c20bf9a3e22b65b5f6f3d9edc852931
• https://git.kernel.org/stable/c/905f06a34f960676e7dc77bea00f2f8fe18177ad
• https://git.kernel.org/stable/c/e66e38d07b31e177ca430758ed97fbc79f27d966