CVE-2015-6031 in MiniUPnP Client
Summary
by MITRE
Buffer overflow in the IGDstartelt function in igd_desc_parse.c in the MiniUPnP client (aka MiniUPnPc) before 1.9.20150917 allows remote UPNP servers to cause a denial of service (application crash) and possibly execute arbitrary code via an "oversized" XML element name.
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Analysis
by VulDB Data Team • 11/18/2024
The vulnerability identified as CVE-2015-6031 represents a critical buffer overflow flaw within the MiniUPnP client library, specifically within the IGDstartelt function located in the igd_desc_parse.c file. This vulnerability affects versions of MiniUPnPc prior to 1.9.20150917 and demonstrates a fundamental weakness in XML parsing logic that can be exploited by remote UPNP servers to compromise system integrity. The flaw occurs when processing XML elements with excessively long names, creating a scenario where the application fails to properly validate input boundaries before attempting to store data in fixed-size buffers.
The technical implementation of this vulnerability stems from inadequate bounds checking during XML element name processing within the Internet Gateway Device (IGD) description parsing functionality. When a remote UPNP server sends a malformed XML response containing an oversized element name, the IGDstartelt function fails to validate the length of the element name against predetermined buffer limits. This allows an attacker to overflow the allocated memory space and overwrite adjacent memory locations, potentially leading to application crashes or more severe consequences including arbitrary code execution. The vulnerability operates at the intersection of XML parsing security and buffer management, making it particularly dangerous in networked environments where UPNP discovery and configuration processes are common.
The operational impact of CVE-2015-6031 extends beyond simple denial of service scenarios, as the buffer overflow could potentially enable remote code execution depending on memory layout and exploitation circumstances. Systems utilizing MiniUPnPc for UPNP functionality become vulnerable to attacks from malicious UPNP servers on the network, particularly in environments where automatic UPNP discovery is enabled. The vulnerability affects a wide range of devices and applications that rely on MiniUPnPc for UPNP client operations, including routers, network appliances, and software applications that implement UPNP client functionality. This makes the attack surface particularly broad and concerning for network administrators managing heterogeneous environments with multiple UPNP-enabled devices.
Mitigation strategies for this vulnerability require immediate patching of affected systems to versions 1.9.20150917 or later, which contain the necessary buffer overflow protections and input validation improvements. Network administrators should implement proper firewall rules to limit UPNP traffic where possible, particularly in sensitive network segments where the risk of exploitation is higher. The vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, and can be mapped to ATT&CK technique T1210 for exploiting buffer overflows in network services. Additional defensive measures include implementing network segmentation, monitoring for unusual UPNP traffic patterns, and ensuring that automatic UPNP discovery is disabled on network devices that do not require UPNP functionality. Organizations should also consider implementing intrusion detection systems that can identify malformed XML traffic patterns associated with this specific vulnerability.