CVE-2012-5961 in portable SDK for UPnP
Summary
by MITRE
Stack-based buffer overflow in the unique_service_name function in ssdp/ssdp_server.c in the SSDP parser in the portable SDK for UPnP Devices (aka libupnp, formerly the Intel SDK for UPnP devices) 1.3.1 allows remote attackers to execute arbitrary code via a long UDN (aka device) field in a UDP packet.
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Analysis
by VulDB Data Team • 06/29/2025
The vulnerability identified as CVE-2012-5961 represents a critical stack-based buffer overflow flaw within the portable SDK for UPnP Devices version 1.3.1, specifically affecting the SSDP (Simple Service Discovery Protocol) parser component. This issue resides in the unique_service_name function located within the ssdp/ssdp_server.c file, which processes UDP packets containing device identification information. The vulnerability manifests when processing a malformed UDP packet containing an excessively long UDN (Unique Device Name) field, creating a condition where attacker-controlled data can overwrite adjacent stack memory locations. The flaw enables remote code execution capabilities, making it particularly dangerous in networked environments where UPnP devices are exposed to untrusted network traffic. This vulnerability directly relates to CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite stack data structures and potentially execute arbitrary code.
The technical implementation of this vulnerability exploits the fundamental design flaw in memory management within the UPnP SDK's SSDP parser. When a UDP packet is received containing a device field that exceeds the allocated buffer size, the function fails to properly validate input length before copying data to the stack buffer. This allows attackers to craft malicious packets with oversized UDN values that overwrite return addresses, function pointers, and other critical stack data. The attack vector operates entirely over UDP protocol, making it accessible to remote adversaries without requiring authentication or privileged access. The vulnerability's exploitation potential aligns with ATT&CK technique T1203, which involves leveraging remote access vulnerabilities to gain code execution privileges. The flaw essentially creates a path where network-based input can be manipulated to overwrite program execution flow, potentially allowing attackers to inject and execute malicious code with the privileges of the affected UPnP service.
The operational impact of CVE-2012-5961 extends beyond simple remote code execution, as it affects a wide range of UPnP-enabled devices and services that utilize the libupnp library. This includes routers, networked printers, media servers, and other internet-connected devices that implement UPnP functionality. The vulnerability can be exploited in various attack scenarios, from unauthorized device compromise to broader network infiltration, particularly in environments where UPnP is enabled by default. The attack requires only network access to the affected device, making it particularly concerning for home and enterprise networks where UPnP services are commonly enabled. Organizations using affected versions of libupnp are at risk of complete device compromise, as attackers can potentially gain persistent access to network infrastructure through this vulnerability. The impact is amplified by the fact that many network devices automatically enable UPnP services, creating numerous potential attack surfaces without explicit user knowledge or consent.
Mitigation strategies for CVE-2012-5961 primarily involve immediate software updates to versions that address the buffer overflow vulnerability, specifically targeting libupnp versions 1.3.2 and later where the issue has been resolved through proper input validation and buffer size enforcement. Network administrators should disable UPnP functionality on devices where it is not required, as this eliminates the attack surface entirely. Implementing network segmentation and access controls can limit the potential impact of exploitation by restricting access to UPnP-enabled devices. Additionally, network monitoring solutions should be configured to detect unusual UDP traffic patterns that may indicate exploitation attempts. The fix implemented in subsequent versions typically involves adding proper bounds checking to the unique_service_name function and implementing input validation that prevents oversized UDN fields from being processed. Security teams should also consider implementing intrusion detection systems that can identify and block malformed UPnP packets attempting to exploit this vulnerability, as the attack pattern is relatively consistent and detectable through network traffic analysis.