A vulnerability, which was classified as critical, has been found in Linux Kernel up to 5.3.2 (Operating System). This issue affects the function ax25_create of the file net/ax25/af_ax25.c of the component AF_AX25 Network Module. The manipulation with an unknown input leads to a default permission vulnerability. Using CWE to declare the problem leads to CWE-276. During installation, installed file permissions are set to allow anyone to modify those files. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

ax25_create in net/ax25/af_ax25.c in the AF_AX25 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-0614e2b73768.

The weakness was disclosed 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 has been coordinated in cooperation with Linux. The identification of this vulnerability is CVE-2019-17052 since 10/01/2019. Attacking locally is a requirement. The successful exploitation needs a simple 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

The entries 142788, 142789, 142790 and 142791 are pretty similar.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.3.0
• 5.3.1
• 5.3.2

License

• open-source

CPE 2.3info

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CPE 2.2info

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