CVE-2023-49582: Apache Portable Runtime Info Disclosure

CVE-2023-49582 Overview

CVE-2023-49582 is an insecure permissions vulnerability in the Apache Portable Runtime (APR) library that affects Unix platforms. The library sets overly permissive access controls on named shared memory segments, allowing local users to read these segments and potentially access sensitive application data. This vulnerability is classified as CWE-732 (Incorrect Permission Assignment for Critical Resource).

Critical Impact

Local users on affected Unix systems can read named shared memory segments created by APR-based applications, potentially exposing sensitive application data including credentials, session tokens, or other confidential information stored in shared memory.

Affected Products

• Apache Portable Runtime (APR) versions prior to 1.7.5 on Unix platforms
• Applications built using APR that utilize named shared memory segments
• Systems without the APR_USE_SHMEM_SHMGET=1 build configuration

Discovery Timeline

• 2024-08-26 - CVE-2023-49582 published to NVD
• 2025-03-13 - Last updated in NVD database

Technical Details for CVE-2023-49582

Vulnerability Analysis

The Apache Portable Runtime library provides a portable abstraction layer for shared memory operations across different operating systems. On Unix platforms, when APR creates named shared memory segments, it assigns overly permissive access rights that allow any local user on the system to read the contents of these segments.

This represents a confidentiality breach where applications relying on APR for shared memory operations may inadvertently expose sensitive data to unauthorized local users. The vulnerability specifically affects the default shared memory implementation and does not impact systems using the alternative SHMGET implementation (enabled via APR_USE_SHMEM_SHMGET=1 in apr.h).

Non-Unix platforms are not affected by this vulnerability as they use different shared memory mechanisms with appropriate permission models.

Root Cause

The root cause is improper permission assignment when creating named shared memory segments on Unix systems. The APR library fails to restrict read access to the creating process or explicitly authorized users, instead allowing world-readable permissions on the shared memory segments. This is a classic CWE-732 vulnerability where critical resources are assigned permissions that violate the principle of least privilege.

Attack Vector

The attack vector is local, requiring an attacker to have user-level access to the target Unix system. Once on the system, the attacker can enumerate and read named shared memory segments created by APR-based applications. The attack requires no special privileges beyond standard user access, no user interaction, and has low complexity.

The exploitation process involves identifying shared memory segments on the system, reading the contents of segments created by vulnerable APR versions, and extracting any sensitive data stored in these segments by target applications.

Detection Methods for CVE-2023-49582

Indicators of Compromise

• Unexpected access patterns to shared memory segments in system audit logs
• Local users querying or reading shared memory segments they should not have access to
• Anomalous use of ipcs or similar shared memory inspection tools by non-administrative users

Detection Strategies

• Monitor for processes accessing shared memory segments created by other users using system auditing facilities
• Review APR library version deployed across systems using package management tools
• Audit applications using APR for shared memory functionality and assess data sensitivity

Monitoring Recommendations

• Enable and review auditd rules for shared memory access on Linux systems
• Implement file integrity monitoring on APR library files to detect unauthorized modifications
• Deploy endpoint detection solutions capable of monitoring inter-process communication patterns

How to Mitigate CVE-2023-49582

Immediate Actions Required

• Upgrade Apache Portable Runtime to version 1.7.5 or later on all affected Unix systems
• Audit applications for sensitive data stored in APR-managed shared memory segments
• Review system access controls to limit local user accounts to only those required

Patch Information

Apache has released APR version 1.7.5 which addresses this vulnerability by implementing proper permission restrictions on named shared memory segments. Users should upgrade to this version or later. For additional information, refer to the Apache Mailing List Thread and the Openwall OSS Security Post. NetApp customers should review the NetApp Security Advisory for product-specific guidance.

Workarounds

• Rebuild APR with APR_USE_SHMEM_SHMGET=1 defined in apr.h to use an alternative shared memory implementation
• Restrict local user access to the system to only trusted users until patching is complete
• Implement additional access controls at the application level for sensitive data handling
• Consider network segmentation to limit lateral movement if shared memory contains network credentials

# Verify APR version on Debian/Ubuntu systems
dpkg -l | grep libapr

# Verify APR version on RHEL/CentOS systems
rpm -qa | grep apr

# Check for APR_USE_SHMEM_SHMGET in APR build configuration
grep -r "APR_USE_SHMEM_SHMGET" /usr/include/apr* 2>/dev/null