CVE-2022-48522 in Perl
Summary
by MITRE • 08/22/2023
In Perl 5.34.0, function S_find_uninit_var in sv.c has a stack-based crash that can lead to remote code execution or local privilege escalation.
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Analysis
by VulDB Data Team • 09/16/2023
The vulnerability identified as CVE-2022-48522 represents a critical stack-based buffer overflow within the Perl 5.34.0 interpreter that exists in the S_find_uninit_var function located in the sv.c source file. This flaw demonstrates a classic software security issue where improper bounds checking during variable initialization detection creates an exploitable condition that can be leveraged by malicious actors. The vulnerability specifically affects the Perl interpreter's handling of uninitialized variables during script execution, creating a scenario where crafted input can trigger memory corruption. The stack-based nature of this overflow indicates that the vulnerability occurs within the interpreter's stack memory management, making it particularly dangerous as it can overwrite critical function return addresses and execution flow control structures. This type of vulnerability falls under CWE-121 Stack-based Buffer Overflow, which is classified as a high-severity issue in the Common Weakness Enumeration catalog and is often exploited in the context of remote code execution scenarios.
The technical exploitation of this vulnerability requires understanding how Perl's variable handling mechanisms operate within the interpreter's memory space. When S_find_uninit_var processes uninitialized variable detection, it appears to fail to properly validate input parameters or buffer sizes, allowing an attacker to craft malicious Perl scripts that cause the interpreter to write beyond allocated stack memory boundaries. The specific conditions that trigger this overflow involve manipulating the interpreter's internal state during variable initialization checks, potentially through crafted data structures or malformed input that causes the function to exceed its intended memory allocation. This vulnerability demonstrates how even seemingly benign interpreter functions can become attack vectors when proper memory management and bounds checking are absent. The flaw's potential for remote code execution stems from the fact that Perl interpreters are commonly used in web applications, server-side scripting, and automated processing environments where untrusted input is frequently processed, making the exploitation surface quite broad.
The operational impact of CVE-2022-48522 extends beyond simple denial of service scenarios as the vulnerability can enable both remote code execution and local privilege escalation depending on the execution context. When exploited in web server environments running Perl-based applications, attackers can potentially execute arbitrary code with the privileges of the web server process, leading to complete system compromise. The privilege escalation aspect becomes particularly concerning when Perl interpreters are executed with elevated privileges, such as when running as root or system services. In local execution contexts, this vulnerability could allow attackers to gain unauthorized access to system resources or escalate their privileges to administrative levels. The vulnerability's exploitation aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter, where attackers leverage Perl's scripting capabilities to execute malicious payloads. Additionally, the attack surface includes scenarios where Perl scripts process user input from web forms, file uploads, or network communications, making this vulnerability particularly dangerous in production environments.
Mitigation strategies for CVE-2022-48522 must address both immediate remediation and long-term security posture improvements. The primary recommendation involves upgrading to Perl versions that have patched this vulnerability, specifically versions beyond 5.34.0 where the S_find_uninit_var function has been properly hardened against buffer overflow conditions. System administrators should implement comprehensive patch management processes that prioritize security updates for interpreter environments, particularly those handling untrusted input. Network segmentation and input validation controls should be enhanced to reduce the attack surface where Perl scripts are executed, implementing strict sanitization of all input data before processing. The vulnerability highlights the importance of memory safety practices and static code analysis in interpreter development, suggesting that organizations should review their Perl-based applications for similar patterns that might introduce other exploitable conditions. Additionally, runtime protection mechanisms such as stack canaries, address space layout randomization, and heap-based memory protection should be enabled to provide additional defense-in-depth layers against potential exploitation attempts. Organizations should also consider implementing automated monitoring for suspicious Perl script execution patterns and establish incident response procedures specifically tailored to handle interpreter-based security incidents.