CVE-2021-43975 : What You Need to Know
Learn about CVE-2021-43975, a critical Linux kernel vulnerability allowing unauthorized out-of-bounds writes. Find mitigation steps and update recommendations here.
In the Linux kernel through version 5.15.2, a vulnerability in drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_utils.c can be exploited by an attacker to trigger an out-of-bounds write.
Understanding CVE-2021-43975
This CVE involves a specific function in the Linux kernel that can be manipulated to perform unauthorized write operations beyond the allocated memory limits.
What is CVE-2021-43975?
The CVE-2021-43975 vulnerability found in the Linux kernel up to version 5.15.2 allows an attacker, by introducing a malicious device, to initiate an out-of-bounds write through a specifically crafted length value.
The Impact of CVE-2021-43975
The potential impact of this vulnerability includes unauthorized modification of memory beyond the intended boundaries, which can lead to system instability, crashes, or potentially remote code execution.
Technical Details of CVE-2021-43975
This section delves into the specifics of the vulnerability.
Vulnerability Description
The flaw resides in the hw_atl_utils_fw_rpc_wait function in drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_utils.c, allowing an attacker to trigger an out-of-bounds write.
Affected Systems and Versions
- Product: Not applicable
- Vendor: Not applicable
- Versions Affected: Up to Linux kernel version 5.15.2
Exploitation Mechanism
The vulnerability can be exploited by an attacker who introduces a carefully crafted device to execute unauthorized write operations outside the permissible memory boundaries.
Mitigation and Prevention
To address CVE-2021-43975, consider the following steps:
Immediate Steps to Take
- Update the Linux kernel to a patched version that addresses the vulnerability.
- Regularly check for security advisories from the Linux kernel and apply patches promptly.
Long-Term Security Practices
- Implement strict device validation mechanisms to prevent the introduction of malicious devices.
- Employ runtime monitoring for detecting and mitigating out-of-bounds write attempts.
Patching and Updates
Ensure timely installation of security patches released by the Linux kernel maintainers to mitigate the risk posed by this vulnerability.