CVE-2016-8863 in libupnp
Summary
by MITRE
Heap-based buffer overflow in the create_url_list function in gena/gena_device.c in Portable UPnP SDK (aka libupnp) before 1.6.21 allows remote attackers to cause a denial of service (crash) or possibly execute arbitrary code via a valid URI followed by an invalid one in the CALLBACK header of an SUBSCRIBE request.
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Analysis
by VulDB Data Team • 10/12/2022
The vulnerability CVE-2016-8863 represents a critical heap-based buffer overflow affecting the Portable UPnP SDK library version 1.6.20 and earlier. This flaw exists within the create_url_list function located in the gena/gena_device.c file, which processes SUBSCRIBE requests in UPnP device implementations. The vulnerability specifically targets the handling of callback URIs within SUBSCRIBE requests, where the system processes a valid URI followed by an invalid one in the CALLBACK header, creating a dangerous condition that can be exploited by remote attackers. The flaw stems from insufficient input validation and memory management when parsing multiple URIs within a single callback header field, allowing attackers to manipulate memory layout and potentially execute arbitrary code.
The technical implementation of this vulnerability demonstrates a classic heap overflow condition where the system allocates memory for URL processing without proper bounds checking. When the create_url_list function encounters the sequence of a valid URI followed by an invalid one, it fails to properly validate the boundary conditions of memory allocation, leading to memory corruption that can result in either immediate crash or more severe exploitation opportunities. The vulnerability operates at the application layer and requires minimal privileges to exploit, making it particularly dangerous in networked environments where UPnP services are exposed. The flaw is categorized under CWE-121 Heap-based Buffer Overflow, which specifically addresses buffer overflows occurring in heap memory regions where insufficient bounds checking allows attackers to overwrite adjacent memory locations.
The operational impact of CVE-2016-8863 extends beyond simple denial of service to potentially enable remote code execution, making it a significant concern for networked devices implementing UPnP functionality. Devices such as routers, network cameras, media servers, and other UPnP-enabled hardware are at risk when running affected versions of the Portable UPnP SDK. The vulnerability can be exploited through standard network traffic without requiring authentication, making it particularly attractive to attackers seeking to compromise network infrastructure. In practical attack scenarios, an attacker can craft malicious SUBSCRIBE requests with carefully constructed callback headers that trigger the buffer overflow condition, potentially leading to system crashes or full compromise of the affected device. The attack vector aligns with ATT&CK technique T1059.007 for command and control communications, as compromised devices could be used for further network infiltration.
Mitigation strategies for CVE-2016-8863 require immediate patching of affected systems to upgrade to Portable UPnP SDK version 1.6.21 or later, which contains the necessary fixes for the buffer overflow condition. Network administrators should implement strict access controls and firewall rules to limit UPnP service exposure, particularly in sensitive network segments. Additional defensive measures include monitoring for unusual SUBSCRIBE request patterns and implementing intrusion detection systems that can identify malformed callback headers. The vulnerability highlights the importance of proper input validation and memory management practices in network service implementations, aligning with security best practices from NIST SP 800-45 and OWASP Top 10 security guidelines. Organizations should also conduct thorough vulnerability assessments of all network devices running UPnP services to identify and remediate similar potential vulnerabilities in their infrastructure.