SB2021072071 - Ubuntu update for linux

Description

This security bulletin contains information about 3 secuirty vulnerabilities.

1) Security features bypass (CVE-ID: CVE-2020-26558)

The vulnerability allows a remote attacker to compromise the target system.

The vulnerability exists due to an impersonation in the Passkey Entry protocol flaw. A remote attacker on the local network can perform a man-in-the-middle (MITM) attack and impersonate the initiating device without any previous knowledge.

Note: This vulnerability affects the following specifications:

• BR/EDR Secure Simple Pairing in Bluetooth Core Specifications 2.1 through 5.2
• BR/EDR Secure Connections Pairing in Bluetooth Core Specifications 4.1 through 5.2 
• LE Secure Connections Pairing in Bluetooth Core Specifications 4.2 through 5.2

2) Improper access control (CVE-ID: CVE-2021-0129)

The vulnerability allows a remote attacker to gain unauthorized access to otherwise restricted functionality.

The vulnerability exists due to improper access restrictions. A remote authenticated attacker on the local network can bypass implemented security restrictions and enable information disclosure

3) Integer overflow (CVE-ID: CVE-2021-33909)

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to integer overflow during size_t-to-int conversion when creating, mounting, and deleting a deep directory structure whose total path length exceeds 1GB. An unprivileged local user can write up to 10-byte string to an offset of exactly -2GB-10B below the beginning of a vmalloc()ated kernel buffer.

Successful exploitation of vulnerability may allow an attacker to exploit the our-of-bounds write vulnerability to execute arbitrary code with root privileges.

Remediation

Install update from vendor's website.

References

• https://ubuntu.com/security/notices/USN-5017-1