CVE-2016-5180 in Android
Summary
by MITRE
Heap-based buffer overflow in the ares_create_query function in c-ares 1.x before 1.12.0 allows remote attackers to cause a denial of service (out-of-bounds write) or possibly execute arbitrary code via a hostname with an escaped trailing dot.
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Analysis
by VulDB Data Team • 09/27/2024
The heap-based buffer overflow vulnerability identified as CVE-2016-5180 affects the c-ares library version 1.x prior to 1.12.0, representing a critical security flaw that can be exploited to cause denial of service or potentially achieve arbitrary code execution. This vulnerability specifically targets the ares_create_query function within the library, which is responsible for creating DNS query structures. The flaw occurs when processing hostnames that contain escaped trailing dots, creating an exploitable condition that can be leveraged by remote attackers to manipulate memory allocation and execution flow.
The technical nature of this vulnerability stems from improper bounds checking within the ares_create_query function where the library fails to adequately validate the length of hostname data containing escaped trailing dots. When such malformed input is processed, the function allocates insufficient heap memory to accommodate the expanded hostname representation, resulting in an out-of-bounds write condition. This heap-based buffer overflow represents a CWE-121 vulnerability type, specifically classified under heap-based buffer overflow conditions where insufficient memory allocation leads to memory corruption. The vulnerability can be triggered through DNS resolution requests that include hostnames with escaped trailing dots, making it particularly dangerous in network services that process external DNS queries.
The operational impact of CVE-2016-5180 extends beyond simple denial of service scenarios to potentially enable remote code execution, making it a severe threat to systems relying on c-ares for DNS resolution. Attackers can exploit this vulnerability by crafting malicious DNS queries containing escaped trailing dots, which when processed by vulnerable applications can lead to memory corruption that may be leveraged for privilege escalation or complete system compromise. The vulnerability affects numerous applications and services that depend on c-ares for DNS functionality, including web servers, mail servers, and network monitoring tools. This makes the impact particularly widespread across enterprise environments where DNS resolution is a fundamental component of network operations.
Systems implementing mitigation strategies should prioritize immediate patching to c-ares version 1.12.0 or later, which contains the necessary fixes for this buffer overflow condition. Organizations should also implement network monitoring to detect suspicious DNS query patterns that may indicate exploitation attempts, and consider input validation measures that filter out malformed hostname entries before they reach the DNS resolution layer. The vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as exploitation may enable attackers to execute arbitrary code on vulnerable systems. Additionally, this vulnerability demonstrates the importance of proper memory management and bounds checking in network libraries, highlighting the need for comprehensive security testing of third-party components used in critical infrastructure applications.