CVE-2016-8705 in Memcached
Summary
by MITRE
Multiple integer overflows in process_bin_update function in Memcached, which is responsible for processing multiple commands of Memcached binary protocol, can be abused to cause heap overflow and lead to remote code execution.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 04/20/2025
The vulnerability identified as CVE-2016-8705 represents a critical security flaw within the Memcached distributed memory object caching system that has significant implications for systems relying on this widely deployed software. This vulnerability specifically targets the process_bin_update function within Memcached's binary protocol implementation, which serves as the core mechanism for processing various commands in the binary interface. The flaw manifests as multiple integer overflows that occur when the system handles certain command parameters, creating a scenario where attacker-controlled input can manipulate memory allocation calculations. These integer overflows fundamentally compromise the integrity of memory management operations within the application's heap structure, creating opportunities for malicious actors to manipulate memory layout and execute arbitrary code remotely. The vulnerability affects Memcached versions prior to 1.4.25 and represents a serious threat to systems where Memcached serves as a critical component in web application architectures.
The technical implementation of this vulnerability stems from insufficient input validation within the process_bin_update function, which processes binary protocol commands that include data size parameters. When Memcached receives commands containing crafted integer values, the system performs arithmetic operations on these parameters without proper overflow checking, leading to scenarios where calculated memory allocation sizes become negative or excessively large. This failure in integer overflow detection creates a condition where the heap allocation functions receive invalid size parameters that can cause memory corruption. The vulnerability is classified under CWE-190, which specifically addresses integer overflow and underflow conditions, and aligns with ATT&CK technique T1059.007 for remote code execution through memory corruption attacks. The flaw demonstrates how seemingly benign parameter handling can become a vector for sophisticated exploitation when proper bounds checking is absent from critical memory management functions.
The operational impact of CVE-2016-8705 extends far beyond simple service disruption, as successful exploitation can result in complete system compromise and unauthorized access to sensitive data stored within Memcached instances. Attackers can leverage this vulnerability to execute arbitrary code on vulnerable systems, potentially gaining administrative privileges and establishing persistent access to network infrastructure. The remote code execution capability means that adversaries need only access to the Memcached service port to potentially take control of affected systems, making this vulnerability particularly dangerous in environments where Memcached is exposed to untrusted networks. The heap overflow conditions created by this flaw can lead to denial of service scenarios, data corruption, and information disclosure, while also providing a pathway for attackers to escalate privileges and move laterally within network environments. Organizations running vulnerable Memcached instances face significant risk of data breaches, service interruptions, and potential compromise of entire application stacks that depend on this caching infrastructure.
Mitigation strategies for CVE-2016-8705 require immediate patching of affected Memcached installations to version 1.4.25 or later, which includes proper integer overflow protections within the process_bin_update function. System administrators should implement network segmentation to restrict access to Memcached ports, ensuring that only trusted applications and systems can communicate with caching services. Additional protective measures include deploying network monitoring solutions to detect anomalous command patterns that might indicate exploitation attempts, and implementing proper firewall rules to limit external access to Memcached instances. The vulnerability highlights the importance of input validation and proper integer handling in security-critical applications, and organizations should review their codebases for similar patterns that might create analogous conditions. Regular security assessments and vulnerability scanning should include checks for outdated Memcached installations, while incident response procedures should be updated to address potential exploitation of heap overflow conditions in caching systems. Organizations should also consider implementing intrusion detection systems specifically designed to identify exploitation attempts targeting memory corruption vulnerabilities in widely used software components.