CVE-2018-20617 in ok-file-formats
Summary
by MITRE
ok-file-formats through 2018-10-16 has a heap-based buffer overflow in the ok_csv_decode2 function in ok_csv.c.
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Analysis
by VulDB Data Team • 04/25/2020
The vulnerability identified as CVE-2018-20617 represents a critical heap-based buffer overflow within the ok-file-formats library version 2018-10-16. This issue specifically affects the ok_csv_decode2 function located in the ok_csv.c source file, creating a potential pathway for remote code execution and system compromise. The flaw arises from inadequate input validation and memory management when processing comma-separated values data structures, making it particularly dangerous in environments where untrusted data is processed through CSV parsing functionality.
The technical nature of this vulnerability falls under CWE-121, heap-based buffer overflow, which occurs when more data is written to a heap-allocated buffer than it can accommodate. In the context of CSV processing, this typically happens when the parser fails to properly validate the length of incoming data fields or when it incorrectly calculates buffer boundaries during parsing operations. The ok_csv_decode2 function appears to allocate memory based on assumptions about input data size that prove incorrect when confronted with malformed or excessively large CSV records, leading to memory corruption that can be exploited by attackers to overwrite adjacent heap memory locations.
From an operational standpoint, this vulnerability poses significant risks to systems that rely on the ok-file-formats library for data processing, particularly those handling external CSV inputs from web applications, data import systems, or automated data ingestion pipelines. The impact extends beyond simple data corruption to potentially enable arbitrary code execution, privilege escalation, and complete system compromise depending on the execution environment. Attackers could exploit this through crafted CSV files that trigger the overflow condition, potentially leading to persistent backdoor access or denial of service scenarios that disrupt critical business operations.
Organizations should implement immediate mitigations including updating to patched versions of the ok-file-formats library, implementing input validation layers that restrict CSV data size and format, and deploying runtime protections such as address space layout randomization and stack canaries. Additionally, network segmentation and access controls should be enforced to limit exposure of systems that process untrusted CSV data. This vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter execution, as exploitation could lead to command injection through compromised processes. Security monitoring should focus on detecting anomalous CSV processing activities and memory corruption patterns that may indicate exploitation attempts. The remediation approach should include comprehensive code review of similar parsing functions and implementation of robust memory safety practices to prevent similar issues in other components of the software supply chain.