CVE-2021-33643 : Security Advisory and Response
Learn about CVE-2021-33643, a critical vulnerability in libtar <=1.2.21 allowing attackers to trigger out-of-bounds reads via crafted tar files. Find mitigation steps here.
An attacker who submits a crafted tar file with size in header struct being 0 may be able to trigger a call to malloc(0) for a variable gnu_longlink, causing an out-of-bounds read.
Understanding CVE-2021-33643
This CVE involves a vulnerability that allows attackers to exploit a crafted tar file to trigger a specific function, leading to an out-of-bounds read.
What is CVE-2021-33643?
The CVE-2021-33643 vulnerability arises when a malicious actor manipulates a tar file in a way that triggers an out-of-bounds read due to incorrect memory allocation.
The Impact of CVE-2021-33643
The impact of this vulnerability is significant as it can be exploited by an attacker to read memory outside of the allocated buffer, potentially leading to unauthorized disclosure of sensitive information.
Technical Details of CVE-2021-33643
This section provides a deeper look into the technical aspects of CVE-2021-33643.
Vulnerability Description
The vulnerability allows an attacker to manipulate a tar file to trigger an out-of-bounds read by causing a call to malloc(0) for a specific variable.
Affected Systems and Versions
The affected product is libtar with versions prior to 1.2.21. Systems using affected versions of libtar are at risk of exploitation.
Exploitation Mechanism
Exploiting this vulnerability involves submitting a carefully crafted tar file with a specific size parameter to trigger the out-of-bounds read.
Mitigation and Prevention
To address CVE-2021-33643, immediate actions and long-term security practices are crucial.
Immediate Steps to Take
Users and administrators should update libtar to version 1.2.21 or newer to mitigate the risk posed by this vulnerability.
Long-Term Security Practices
Regularly updating software components and monitoring security bulletins can help prevent similar vulnerabilities in the future.
Patching and Updates
Stay informed about security updates for libtar and promptly apply patches to ensure that systems are protected against known vulnerabilities.