CVE-2023-35803: Extreme IQ Engine Buffer Overflow Flaw

CVE-2023-35803 Overview

CVE-2023-35803 is a critical buffer overflow vulnerability affecting Extreme Networks IQ Engine before version 10.6r2 on Extreme Network AP devices. The vulnerability exists in the ACSD (Automatic Channel Selection Daemon) service and can be exploited remotely without authentication. Due to the network-accessible nature of this flaw, attackers can potentially achieve complete compromise of affected access point devices, leading to unauthorized access to enterprise wireless infrastructure.

Critical Impact

This buffer overflow vulnerability allows unauthenticated remote attackers to potentially execute arbitrary code on affected Extreme Networks access points, compromising network infrastructure security and enabling lateral movement within enterprise environments.

Affected Products

• Extreme Networks IQ Engine (versions before 10.6r2)
• Extreme Networks AP3000, AP3000X, AP302W
• Extreme Networks AP305C, AP305C-1, AP305CX
• Extreme Networks AP4000, AP4000-1, AP410C, AP410C-1
• Extreme Networks AP460C, AP460S12C, AP460S6C
• Extreme Networks AP5010, AP5050D, AP5050U
• Extreme Networks AP510C, AP510CX
• Extreme Networks AP630, AP650, AP650X
• Extreme Networks AP1130, AP122, AP130
• Extreme Networks AP150W, AP250, AP30, AP550

Discovery Timeline

• 2023-10-04 - CVE-2023-35803 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2023-35803

Vulnerability Analysis

This vulnerability is classified as CWE-120 (Buffer Copy without Checking Size of Input), commonly known as a classic buffer overflow. The flaw resides in the ACSD (Automatic Channel Selection Daemon) service component of Extreme Networks IQ Engine. When processing input data, the service fails to properly validate the size of incoming data before copying it to a fixed-size buffer, allowing an attacker to overflow the buffer boundaries.

Buffer overflow vulnerabilities of this nature are particularly dangerous in network infrastructure devices because they can allow attackers to overwrite adjacent memory, potentially corrupting program control flow data such as return addresses or function pointers. This can lead to arbitrary code execution with the privileges of the vulnerable service.

Root Cause

The root cause of CVE-2023-35803 is improper bounds checking in the ACSD service within IQ Engine. When the service receives network input, it copies data into a stack or heap buffer without first verifying that the input size does not exceed the allocated buffer capacity. This lack of input validation enables an attacker to supply oversized data that overwrites memory beyond the buffer's intended boundaries.

Attack Vector

The vulnerability is exploitable over the network without requiring authentication or user interaction. An attacker with network access to an affected Extreme Networks access point can send specially crafted packets to the ACSD service. The attack can be executed remotely from any system that can reach the vulnerable service endpoint. Successful exploitation could result in:

• Complete device compromise with full control over the access point
• Execution of arbitrary code in the context of the vulnerable service
• Potential pivot point for further attacks within the network
• Denial of service through system crash or instability

The attack complexity is low, and no special privileges or user interaction are required, making this vulnerability highly exploitable in exposed environments.

Detection Methods for CVE-2023-35803

Indicators of Compromise

• Unexpected crashes or restarts of the ACSD service on Extreme Networks AP devices
• Anomalous network traffic patterns targeting access points on ACSD service ports
• Unusual memory consumption or process behavior on affected devices
• Unexpected outbound connections from access point devices

Detection Strategies

• Monitor network traffic for abnormally large packets or malformed requests destined for Extreme Networks access points
• Implement network intrusion detection rules to identify buffer overflow exploitation attempts against ACSD service
• Deploy network segmentation to limit direct access to AP management interfaces
• Enable comprehensive logging on network infrastructure devices and forward logs to SIEM for analysis

Monitoring Recommendations

• Configure alerts for access point service crashes or unexpected reboots
• Monitor for unauthorized configuration changes on affected devices
• Implement baseline monitoring for normal traffic patterns to AP devices and alert on deviations
• Review access point logs regularly for signs of exploitation attempts

How to Mitigate CVE-2023-35803

Immediate Actions Required

• Upgrade IQ Engine to version 10.6r2 or later immediately on all affected access points
• Restrict network access to AP management interfaces using firewall rules and network segmentation
• Isolate vulnerable devices from untrusted network segments until patching is complete
• Monitor affected devices for signs of compromise while preparing for updates

Patch Information

Extreme Networks has released IQ Engine version 10.6r2 to address this vulnerability. Organizations should apply this update to all affected access point devices as soon as possible. Detailed patch information and upgrade instructions are available in the Extreme Networks Security Advisory SA-2023-067.

Workarounds

• Implement strict network access controls to limit which systems can communicate with AP management interfaces
• Deploy network-level filtering to block potentially malicious traffic to affected services
• Use VLANs and firewall rules to segment AP management traffic from general network access
• Consider disabling the ACSD service if automatic channel selection is not required (consult Extreme Networks documentation for guidance)

# Example: Network segmentation using firewall rules
# Restrict access to AP management interfaces to authorized management stations only
iptables -A INPUT -s <management_network> -d <ap_network> -j ACCEPT
iptables -A INPUT -d <ap_network> -j DROP