SB2021072261 - Red Hat Enterprise Linux 7.4 update for kernel



SB2021072261 - Red Hat Enterprise Linux 7.4 update for kernel

Published: July 22, 2021 Updated: August 9, 2022

Security Bulletin ID SB2021072261
Severity
Medium
Patch available
YES
Number of vulnerabilities 4
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

Medium 25% Low 75%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 4 secuirty vulnerabilities.


1) Path traversal (CVE-ID: CVE-2020-28374)

The vulnerability allows a remote user to perform directory traversal attacks.

The vulnerability exists due to input validation error when processing directory traversal sequences in drivers/target/target_core_xcopy.c in the Linux kernel. A remote user with access to iSCSI LUN can send a specially crafted XCOPY request and read or write arbitrary files on the system.



2) Use-after-free (CVE-ID: CVE-2021-3347)

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

The vulnerability exists due to a use-after-free error when handling PI futexes. A local user can run a specially crafted program to trigger a use-after-free error and execute arbitrary code with elevated privileges.



3) Use-after-free (CVE-ID: CVE-2021-33034)

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

The vulnerability exists due to a use-after-free error in net/bluetooth/hci_event.c when destroying an hci_chan. A local user can escalate privileges on the system.



4) 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.