CVE-2023-5869: PostgreSQL RCE Vulnerability

CVE-2023-5869 Overview

A critical integer overflow vulnerability has been identified in PostgreSQL that allows authenticated database users to execute arbitrary code on the target system. The flaw exists due to missing overflow checks during SQL array value modification operations. When a remote authenticated user provides specially crafted data during array modification, an integer overflow condition can be triggered that corrupts memory, enabling the attacker to write arbitrary bytes to memory and extensively read the server's memory.

This vulnerability is particularly concerning because it can be exploited by any authenticated database user, regardless of their privilege level within the database. Successful exploitation can lead to complete system compromise, including unauthorized data access, data manipulation, and service disruption.

Critical Impact

Authenticated attackers can achieve arbitrary code execution on PostgreSQL servers through integer overflow during array operations, potentially leading to complete system compromise.

Affected Products

• PostgreSQL (versions prior to 16.1, 15.5, 14.10, 13.13, 12.17, and 11.22)
• Red Hat Enterprise Linux 7, 8, and 9 (including EUS, AUS, and TUS variants)
• Red Hat CodeReady Linux Builder
• Red Hat Software Collections

Discovery Timeline

• December 10, 2023 - CVE-2023-5869 published to NVD
• November 4, 2025 - Last updated in NVD database

Technical Details for CVE-2023-5869

Vulnerability Analysis

This vulnerability exists within PostgreSQL's array handling code, specifically in the routines responsible for modifying SQL array values. PostgreSQL arrays support multi-dimensional structures with variable bounds, and the code responsible for calculating memory requirements during array modification operations fails to properly validate integer arithmetic operations.

When array dimensions or element counts are manipulated to produce values that exceed the maximum representable integer, the calculation wraps around due to integer overflow. This results in a smaller-than-required memory allocation, creating a heap buffer overflow condition when the actual array data is written to the undersized buffer.

The impact of this vulnerability extends beyond simple denial of service. An authenticated attacker can leverage the integer overflow to achieve controlled memory corruption, enabling:

• Arbitrary code execution - Writing executable code to memory regions
• Information disclosure - Reading sensitive server memory contents
• Privilege escalation - Gaining elevated privileges within the database or operating system

Root Cause

The root cause is classified as CWE-190 (Integer Overflow or Wraparound). PostgreSQL's array modification functions perform arithmetic operations on user-controllable array dimension values without adequate bounds checking. When calculating the total memory size required for array operations, the multiplication of array dimensions and element sizes can produce results that overflow 32-bit or 64-bit integer boundaries, causing the calculated size to wrap to a small positive value.

Attack Vector

The attack requires network access to a PostgreSQL server and valid database credentials. The attacker constructs a malicious SQL query containing specially crafted array modification operations with dimension values designed to trigger the integer overflow. The attack does not require elevated database privileges—any authenticated user can exploit this vulnerability.

The exploitation process involves:

1. Establishing an authenticated connection to the PostgreSQL database
2. Constructing array operations with carefully calculated dimensions to trigger integer overflow
3. Causing memory corruption through the undersized buffer allocation
4. Leveraging the corruption to execute arbitrary code or read sensitive memory

-- Conceptual attack pattern (sanitized)
-- Attacker crafts array modification with overflow-inducing dimensions
-- The array_cat or similar function receives specially crafted input
-- Integer overflow occurs during size calculation, leading to heap corruption
-- See PostgreSQL security advisory for technical details

Detection Methods for CVE-2023-5869

Indicators of Compromise

• Unusual PostgreSQL crashes or segmentation faults, particularly during array operations
• Unexpected memory access patterns in PostgreSQL process memory
• Database queries containing exceptionally large array dimension specifications
• Error logs showing memory corruption or heap-related failures

Detection Strategies

• Monitor PostgreSQL logs for unusual error patterns related to array operations and memory allocation failures
• Implement database activity monitoring to detect queries with abnormally large array operations
• Deploy endpoint detection solutions capable of identifying memory corruption exploitation attempts
• Establish baseline metrics for PostgreSQL process behavior and alert on deviations

Monitoring Recommendations

• Enable comprehensive PostgreSQL logging including statement logging for suspicious query patterns
• Configure memory monitoring for PostgreSQL processes to detect unusual allocation patterns
• Implement network-level monitoring to identify potential exploitation attempts from authenticated sessions
• Use SentinelOne's behavioral AI to detect post-exploitation activities following successful code execution

How to Mitigate CVE-2023-5869

Immediate Actions Required

• Update PostgreSQL to patched versions: 16.1, 15.5, 14.10, 13.13, 12.17, or 11.22 immediately
• Review and restrict database user accounts to minimize the number of authenticated users
• Implement network segmentation to limit access to PostgreSQL servers from untrusted networks
• Enable enhanced logging to detect exploitation attempts while patches are being applied

Patch Information

PostgreSQL has released security patches addressing this vulnerability across all supported major versions. Organizations should upgrade to the following minimum versions:

• PostgreSQL 16.x: Upgrade to 16.1 or later
• PostgreSQL 15.x: Upgrade to 15.5 or later
• PostgreSQL 14.x: Upgrade to 14.10 or later
• PostgreSQL 13.x: Upgrade to 13.13 or later
• PostgreSQL 12.x: Upgrade to 12.17 or later
• PostgreSQL 11.x: Upgrade to 11.22 or later

For Red Hat Enterprise Linux deployments, apply the relevant security advisories including RHSA-2023:7545, RHSA-2023:7579, and related updates. Refer to the PostgreSQL Security Advisory for complete patching guidance.

Workarounds

• Restrict network access to PostgreSQL instances using firewall rules to limit exposure to trusted networks only
• Review and revoke database access for unnecessary user accounts to reduce the authenticated attack surface
• Implement application-level input validation to limit array sizes before they reach the database
• Consider deploying a database proxy or Web Application Firewall to filter potentially malicious queries

# Example: Restrict PostgreSQL network access via pg_hba.conf
# Limit connections to specific trusted subnets
# Edit /var/lib/pgsql/data/pg_hba.conf

# TYPE  DATABASE  USER  ADDRESS         METHOD
# Only allow connections from trusted internal network
host    all       all   192.168.1.0/24  scram-sha-256
# Reject all other connections
host    all       all   0.0.0.0/0       reject