Linux Kernel up to 5.3.2 AF_NFC Network net/nfc/llcp_sock.c llcp_sock_create default permission

Summaryinfo

A vulnerability was found in Linux Kernel up to 5.3.2. It has been classified as critical. Affected by this vulnerability is the function llcp_sock_create of the file net/nfc/llcp_sock.c of the component AF_NFC Network Module. Performing a manipulation results in default permission. This vulnerability is identified as CVE-2019-17056. The attack is only possible with local access. There is not any exploit available. It is recommended to apply a patch to fix this issue.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.3.2 (Operating System). It has been classified as critical. This affects the function llcp_sock_create of the file net/nfc/llcp_sock.c of the component AF_NFC Network Module. The manipulation with an unknown input leads to a default permission vulnerability. CWE is classifying the issue as CWE-276. During installation, installed file permissions are set to allow anyone to modify those files. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

llcp_sock_create in net/nfc/llcp_sock.c in the AF_NFC network module in the Linux kernel through 5.3.2 does not enforce CAP_NET_RAW, which means that unprivileged users can create a raw socket, aka CID-3a359798b176.

The weakness was released 10/01/2019 by Ori Nimron as confirmed git commit (GIT Repository). It is possible to read the advisory at git.kernel.org. The public release was coordinated with Linux. This vulnerability is uniquely identified as CVE-2019-17056 since 10/01/2019. Attacking locally is a requirement. The requirement for exploitation is a authentication. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1222 according to MITRE ATT&CK. The advisory points out:

Ori Nimron pointed out that there are a number of places in the kernel where you can create a raw socket, without having to have the CAP_NET_RAW permission.

Applying a patch is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The vulnerability will be addressed with the following lines of code:

if (!capable(CAP_NET_RAW))
   return -EPERM;

To resolve this, here's a short patch series to test these odd and old protocols for this permission before allowing the creation to succeed

Entries connected to this vulnerability are available at VDB-142787, VDB-142788, VDB-142789 and VDB-142790. Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.3.0
• 5.3.1
• 5.3.2

License

• open-source

Website

• Vendor: https://www.kernel.org/

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Be aware that VulDB is the high quality source for vulnerability data.

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