CVE-2022-3715: GNU Bash Buffer Overflow Vulnerability

CVE-2022-3715 Overview

A heap-buffer overflow vulnerability has been identified in the GNU Bash package, specifically within the valid parameter_transform function. This memory corruption flaw can allow attackers with local access to trigger buffer overflows that may lead to memory corruption, potential code execution, or denial of service conditions on affected systems.

Critical Impact

This heap-buffer overflow vulnerability in bash's parameter transformation functionality could allow local attackers to corrupt memory, potentially leading to arbitrary code execution with the privileges of the running bash process or causing system instability.

Affected Products

• GNU Bash (all versions prior to patch)
• Red Hat Enterprise Linux 9.0

Discovery Timeline

• 2023-01-05 - CVE-2022-3715 published to NVD
• 2025-11-03 - Last updated in NVD database

Technical Details for CVE-2022-3715

Vulnerability Analysis

The vulnerability exists in the valid parameter_transform function within GNU Bash. This function is responsible for handling parameter expansion and transformation operations, which are fundamental to bash's string manipulation capabilities. The flaw occurs when the function fails to properly validate the boundaries of heap-allocated memory buffers during parameter transformation operations.

When processing specially crafted input during parameter expansion, the function can write beyond the allocated buffer boundaries on the heap. This out-of-bounds write condition (CWE-787) represents a classic memory corruption vulnerability pattern (CWE-119) that has historically been associated with serious security implications in shell interpreters.

The local attack vector requires an attacker to have the ability to execute bash scripts or commands on the target system. However, in environments where bash processes untrusted input or scripts, this vulnerability could be leveraged to escalate privileges or compromise system integrity.

Root Cause

The root cause stems from insufficient bounds checking in the valid parameter_transform function when handling parameter expansion operations. The function allocates a heap buffer for transformation results but fails to properly validate that write operations remain within the allocated buffer size. This allows specially crafted parameter transformation requests to overflow the buffer boundaries, corrupting adjacent heap memory structures.

Attack Vector

The attack requires local access to execute bash commands or scripts on the target system. An attacker could exploit this vulnerability by:

1. Crafting malicious parameter expansion expressions that trigger the vulnerable code path
2. Supplying input to bash scripts that perform parameter transformations on attacker-controlled data
3. Leveraging setuid bash scripts or other privileged bash execution contexts

The exploitation complexity is considered low as triggering the heap overflow requires only the ability to pass specially crafted input to bash's parameter expansion functionality. No user interaction is required beyond the attacker's own actions.

Detection Methods for CVE-2022-3715

Indicators of Compromise

• Unexpected bash process crashes or segmentation faults during script execution
• Anomalous memory allocation patterns in bash processes
• Core dumps generated by bash processes indicating heap corruption
• Unusual bash process behavior including unexpected child process spawning

Detection Strategies

• Monitor for bash process crashes and analyze core dumps for heap corruption signatures
• Implement memory protection tools (ASLR, heap guards) and monitor for bypass attempts
• Deploy endpoint detection solutions capable of identifying memory corruption exploitation attempts
• Review system logs for bash-related segmentation faults or memory errors

Monitoring Recommendations

• Enable audit logging for bash script execution on sensitive systems
• Monitor process memory usage patterns for anomalous heap allocation behavior
• Configure crash reporting to capture and analyze bash process failures
• Deploy runtime application self-protection (RASP) solutions where applicable

How to Mitigate CVE-2022-3715

Immediate Actions Required

• Update GNU Bash to the latest patched version from your distribution vendor
• Apply Red Hat Enterprise Linux security updates for affected RHEL 9.0 systems
• Review and restrict execution of untrusted bash scripts on production systems
• Consider using alternative shells for processing untrusted input where possible

Patch Information

Organizations should apply vendor-provided security updates as soon as available. For Red Hat Enterprise Linux systems, refer to the Red Hat Bug Report #2126720 for specific patch information. NetApp customers should review the NetApp Security Advisory #20241108-0002 for guidance on affected NetApp products.

Contact your Linux distribution vendor for the appropriate bash security update packages for your specific platform and version.

Workarounds

• Restrict execution of untrusted bash scripts and limit parameter expansion on untrusted input
• Implement input validation and sanitization before passing data to bash parameter transformations
• Use restricted shell environments (rbash) where full bash functionality is not required
• Enable operating system memory protection features including ASLR and stack canaries

# Configuration example - Verify bash version and enable memory protections
# Check current bash version
bash --version

# Verify ASLR is enabled on Linux systems
cat /proc/sys/kernel/randomize_va_space
# Should return 2 for full randomization

# Enable ASLR if disabled
echo 2 | sudo tee /proc/sys/kernel/randomize_va_space