CVE-2017-7860 in gRPC
Summary
by MITRE
Google gRPC before 2017-02-22 has an out-of-bounds write caused by a heap-based buffer overflow related to the parse_unix function in core/ext/client_channel/parse_address.c.
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Analysis
by VulDB Data Team • 11/29/2022
The vulnerability identified as CVE-2017-7860 represents a critical heap-based buffer overflow within Google gRPC library versions prior to the 2017-02-22 release. This flaw exists in the parse_unix function located within the core/ext/client_channel/parse_address.c file, which forms part of the core client channel functionality that gRPC uses to establish and manage network connections. The out-of-bounds write condition occurs when the library processes Unix domain socket addresses, specifically when handling malformed or improperly formatted address strings that exceed the allocated buffer boundaries. This type of vulnerability falls under CWE-121, heap-based buffer overflow, and represents a fundamental memory safety issue that can lead to arbitrary code execution or system instability. The vulnerability is particularly concerning because gRPC is widely used across enterprise applications for inter-service communication, making it a prime target for exploitation.
The technical implementation of this vulnerability stems from inadequate input validation within the parse_unix function, which fails to properly bounds-check the length of address strings before copying them into fixed-size buffers. When an attacker provides a maliciously crafted Unix socket address that exceeds the expected buffer size, the function continues to write data beyond the allocated memory boundaries, potentially overwriting adjacent memory regions including stack canaries, return addresses, or other critical program data. This memory corruption can be exploited through various attack vectors including remote code execution, denial of service, or privilege escalation depending on the execution context. The vulnerability operates at the application layer and requires no special privileges to exploit, making it particularly dangerous in environments where gRPC services are exposed to untrusted network traffic.
The operational impact of CVE-2017-7860 extends beyond simple system crashes or service disruptions, as it provides attackers with the capability to execute arbitrary code on affected systems. In enterprise environments where gRPC is used extensively for microservices communication, this vulnerability could enable attackers to compromise entire service ecosystems by targeting a single vulnerable endpoint. The exploitability of this vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as successful exploitation could allow attackers to execute arbitrary commands on the affected systems. Organizations using gRPC in production environments face significant risk of data breaches, service interruptions, and potential lateral movement within their network infrastructure, particularly when the vulnerable services are exposed to external networks or when internal services communicate with untrusted endpoints.
Mitigation strategies for CVE-2017-7860 primarily involve immediate patching of all affected gRPC installations to version 2017-02-22 or later, which contains the necessary memory bounds checking and input validation fixes. Organizations should implement comprehensive vulnerability management processes that include regular security assessments of all gRPC-dependent applications and services. Network segmentation and access controls should be enforced to limit exposure of gRPC endpoints to trusted networks only, while monitoring systems should be deployed to detect anomalous traffic patterns that might indicate exploitation attempts. Additionally, developers should implement defensive programming practices including input validation, bounds checking, and memory safety measures when working with gRPC libraries, and should consider using memory safety tools and static analysis to identify similar vulnerabilities in custom implementations. The remediation process should include thorough testing of patched environments to ensure that the fix does not introduce regressions in service functionality while maintaining the security improvements necessary to protect against this specific buffer overflow vulnerability.