CVE-2023-25097 in UR32L
Summary
by MITRE • 07/06/2023
Multiple buffer overflow vulnerabilities exist in the vtysh_ubus binary of Milesight UR32L v32.3.0.5 due to the use of an unsafe sprintf pattern. A specially crafted HTTP request can lead to arbitrary code execution. An attacker with high privileges can send HTTP requests to trigger these vulnerabilities.This buffer overflow occurs in the set_qos function with the attach_class variable.
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Analysis
by VulDB Data Team • 11/06/2025
The CVE-2023-25097 vulnerability represents a critical buffer overflow flaw in the Milesight UR32L v32.3.0.5 network device firmware, specifically within the vtysh_ubus binary component. This vulnerability stems from improper input validation and unsafe string handling practices that create exploitable conditions for remote code execution. The flaw manifests in the set_qos function where the attach_class variable is processed using an unsafe sprintf pattern, creating a classic buffer overflow condition that can be triggered through malicious HTTP requests. The vulnerability's severity is amplified by its accessibility through the web interface, making it particularly dangerous for network administrators who rely on web-based management interfaces for device configuration and monitoring.
The technical exploitation of this vulnerability follows a well-established pattern that aligns with CWE-121 buffer overflow conditions, where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The use of sprintf without proper length validation creates an opportunity for attackers to craft HTTP requests that exceed the allocated buffer space, potentially overwriting return addresses, function pointers, or other critical memory structures. This unsafe string manipulation technique directly maps to ATT&CK tactic TA0002 (Execution) and technique T1059.007 (Command and Scripting Interpreter: PowerShell) when considering the potential for arbitrary code execution. The vulnerability's exploitation requires an attacker with high privileges, suggesting that the device's web interface authentication mechanisms may have already been compromised, or that the device is accessible from untrusted networks.
The operational impact of CVE-2023-25097 extends beyond simple remote code execution, as it provides attackers with potential persistence mechanisms within network infrastructure devices. Once exploited, attackers can manipulate Quality of Service configurations, potentially disrupting network traffic or creating backdoor access points within the network. The vulnerability affects Milesight UR32L devices running firmware version 32.3.0.5, which may be deployed in enterprise networks where these devices serve as critical infrastructure components for network management and monitoring. The attack vector through HTTP requests indicates that the device's web interface is exposed to network traffic, making it susceptible to exploitation from external networks without requiring physical access or additional authentication credentials.
Mitigation strategies for CVE-2023-25097 should prioritize immediate firmware updates from Milesight to address the underlying buffer overflow conditions. Network administrators should implement strict network segmentation to limit access to devices running vulnerable firmware, particularly restricting HTTP access to trusted administrative networks. The implementation of web application firewalls and network access controls can help prevent unauthorized HTTP requests from reaching affected devices. Additionally, monitoring for unusual HTTP traffic patterns or attempts to access the device's management interface can help detect potential exploitation attempts. Security teams should also consider disabling unnecessary web management interfaces and implementing multi-factor authentication for administrative access to reduce the attack surface. The vulnerability's classification as a buffer overflow aligns with industry best practices for vulnerability remediation, emphasizing the importance of proper input validation, bounds checking, and secure coding practices to prevent similar issues in future development cycles.