CVE-2018-14736 in PBC
Summary
by MITRE
An issue was discovered in libpbc.a in cloudwu PBC through 2017-03-02. A buffer over-read can occur in pbc_wmessage_string in wmessage.c for PTYPE_ENUM.
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Analysis
by VulDB Data Team • 04/27/2023
The vulnerability identified as CVE-2018-14736 represents a critical buffer over-read flaw within the libpbc.a library, specifically affecting the cloudwu PBC implementation through March 2, 2017. This issue manifests within the pbc_wmessage_string function located in the wmessage.c source file, where improper bounds checking allows for memory access beyond allocated buffer boundaries. The vulnerability is particularly concerning as it affects the PTYPE_ENUM data type handling within the protocol buffer implementation, which forms the foundation for structured data serialization in numerous applications. The flaw stems from inadequate validation of input parameters during message processing, creating a scenario where maliciously crafted data can trigger unauthorized memory access patterns that may lead to system instability or information disclosure.
The technical implementation of this vulnerability operates through a classic buffer over-read condition that falls under CWE-125, which defines improper output validation of memory buffers. When the pbc_wmessage_string function processes ENUM type data, it fails to properly verify the length of input strings against allocated buffer space, allowing an attacker to provide oversized data that exceeds the intended buffer boundaries. This creates a scenario where adjacent memory locations become accessible through the over-read operation, potentially exposing sensitive information or enabling further exploitation techniques. The vulnerability specifically impacts the write message functionality within the protocol buffer framework, where the system attempts to serialize enum values into memory structures without adequate bounds enforcement.
From an operational standpoint, this vulnerability presents significant risks to systems utilizing the affected libpbc.a library, particularly in environments where protocol buffer serialization is prevalent. The impact extends beyond simple memory corruption to potentially enable information leakage, as the over-read may expose stack contents, heap data, or other sensitive memory regions. Attackers could leverage this weakness to gather intelligence about system memory layout, potentially aiding in more sophisticated exploitation techniques. The vulnerability's presence in cloudwu PBC through March 2017 indicates a prolonged window of exposure, suggesting that numerous applications and systems may have remained vulnerable for extended periods without proper patching or mitigation.
Mitigation strategies for CVE-2018-14736 should prioritize immediate library updates to versions that address the buffer over-read condition in the pbc_wmessage_string function. Organizations must conduct comprehensive inventory assessments to identify all systems utilizing the affected libpbc.a implementation, particularly those handling protocol buffer data serialization. The remediation process should include implementing proper bounds checking mechanisms within the affected code paths, ensuring that all input data for PTYPE_ENUM values is validated against allocated buffer sizes before memory operations occur. Additionally, system hardening measures such as address space layout randomization and stack canaries should be considered as defensive measures against potential exploitation attempts. Security teams should also implement monitoring protocols to detect anomalous memory access patterns that may indicate exploitation attempts targeting this specific vulnerability, aligning with ATT&CK technique T1059 for process injection and T1068 for exploit development against memory corruption vulnerabilities.