Heap Buffer Overflow in Perl Affects Multiple Versions

CVE-2024-56406

What is CVE-2024-56406?

CVE-2024-56406 is a significant vulnerability identified in specific versions of the Perl programming language, which is widely used for web development, network programming, and system administration tasks. This vulnerability manifests as a heap buffer overflow, which can occur when the tr operator processes non-ASCII bytes on the left-hand side of the operation. The overflow can adversely affect an organization by potentially leading to Denial of Service (DoS) attacks or allowing the execution of arbitrary code whereby an attacker could gain uncontrolled access to the affected systems.

Technical Details

The vulnerability arises from an oversight in the handling of memory allocation when processing strings in Perl versions 5.34, 5.36, 5.38, and 5.40, including development builds from 5.33.1 through 5.41.10. Specifically, the function S_do_trans_invmap is responsible for character translation within Perl's tr operator. When large non-ASCII byte sequences are passed as input, the destination pointer d may exceed its allocated bounds, resulting in a heap buffer overflow. This overflow can cause the program to crash, leading to segmentation faults, and serves as a vector for potential attacks if exploited by a malicious actor.

Potential impact of CVE-2024-56406

1. Denial of Service (DoS): The overflow can cause Perl applications to crash, resulting in service interruptions and affecting the availability of services dependent on the affected versions.

2. Arbitrary Code Execution: In environments lacking sufficient security defenses, the vulnerability may allow attackers to execute arbitrary code on affected systems, leading to unauthorized system access and control.

3. Increased Attack Surface: The existence of this vulnerability in commonly used versions of Perl broadens the attack surface for organizations, making it crucial for users to remain vigilant and apply patches promptly to mitigate risk.

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