CVE-2016-4429 in Fujitsu M10-1
Summary
by MITRE
Stack-based buffer overflow in the clntudp_call function in sunrpc/clnt_udp.c in the GNU C Library (aka glibc or libc6) allows remote servers to cause a denial of service (crash) or possibly unspecified other impact via a flood of crafted ICMP and UDP packets.
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Analysis
by VulDB Data Team • 03/04/2025
The vulnerability identified as CVE-2016-4429 represents a critical stack-based buffer overflow within the GNU C Library's implementation of the clntudp_call function in sunrpc/clnt_udp.c. This flaw exists in the core networking components that handle UDP client communications for remote procedure calls, making it a fundamental security issue that affects systems relying on glibc for network operations. The vulnerability specifically manifests when processing crafted network packets, particularly those involving ICMP and UDP protocols, creating a scenario where remote attackers can exploit this weakness to disrupt system functionality. The issue stems from inadequate input validation and bounds checking within the function responsible for handling UDP client calls, allowing malicious packet data to overwrite adjacent memory locations on the stack. This type of vulnerability falls under CWE-121, which addresses stack-based buffer overflow conditions, and represents a classic example of how insufficient validation of network input can lead to system instability. The attack vector specifically involves flooding the target system with carefully crafted packets that trigger the buffer overflow during processing, potentially causing the application or system to crash.
The operational impact of CVE-2016-4429 extends beyond simple denial of service to potentially encompass more severe consequences depending on system configuration and execution context. When exploited successfully, the buffer overflow can cause the affected process to crash, leading to service disruption and potential availability issues for network-dependent applications. The vulnerability's ability to cause system instability makes it particularly dangerous in environments where continuous availability is critical, such as enterprise servers, network infrastructure devices, or any system where glibc-based applications handle network communications. The nature of the flaw means that even a single malicious packet could potentially trigger the overflow, though the described attack typically requires a flood of crafted packets to be effective. This makes the vulnerability particularly concerning for systems that do not implement proper network filtering or rate limiting mechanisms, as attackers could easily overwhelm systems with minimal resources. The vulnerability's classification under the ATT&CK framework would align with techniques involving service stoppage and resource exhaustion, making it a relevant concern for security teams implementing threat detection and response protocols.
Mitigation strategies for CVE-2016-4429 primarily focus on updating the affected glibc components to versions that contain the necessary patches addressing the buffer overflow. System administrators should prioritize applying security updates from trusted sources, ensuring that all systems running glibc-based applications receive the appropriate patches. Network-level mitigations can include implementing rate limiting on UDP and ICMP traffic, configuring firewalls to drop suspicious packets, and deploying intrusion detection systems that can identify and block the specific packet patterns associated with this vulnerability. Additionally, organizations should consider implementing network segmentation to limit the exposure of systems that may be vulnerable, particularly those handling remote procedure calls or network services that rely on the affected functions. The patching process should be carefully managed to avoid introducing compatibility issues with existing applications, and thorough testing should be performed in controlled environments before widespread deployment. Organizations should also monitor their systems for signs of exploitation attempts and maintain appropriate logging mechanisms to detect potential attacks. The vulnerability's nature suggests that preventive measures should include regular security assessments of network services and ensuring that all system components are kept up to date with the latest security patches. Proper input validation and bounds checking in network applications can also serve as additional defensive layers, though the primary remediation must focus on updating the vulnerable glibc implementation itself.