CVE-2018-19490 in Gnuplot
Summary
by MITRE
An issue was discovered in datafile.c in Gnuplot 5.2.5. This issue allows an attacker to conduct a heap-based buffer overflow with an arbitrary amount of data in df_generate_ascii_array_entry. To exploit this vulnerability, an attacker must pass an overlong string as the right bound of the range argument that is passed to the plot function.
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Analysis
by VulDB Data Team • 06/11/2023
The vulnerability identified as CVE-2018-19490 represents a critical heap-based buffer overflow in Gnuplot version 5.2.5, specifically within the datafile.c component. This flaw exists in the df_generate_ascii_array_entry function where the software fails to properly validate input length when processing range arguments passed to the plot function. The vulnerability stems from inadequate bounds checking mechanisms that permit attackers to supply excessively long strings as the right bound parameter, leading to memory corruption that can be exploited for arbitrary code execution.
This heap-based buffer overflow manifests when an attacker constructs a malicious plot command containing an overlong string in the range specification. The flaw operates at the intersection of improper input validation and memory management, where the application allocates insufficient heap space for processing user-supplied data. The vulnerability directly maps to CWE-121, heap-based buffer overflow, and can be categorized under CWE-787, out-of-bounds write, as the overflow occurs when attempting to write beyond allocated heap memory boundaries. The technical implementation involves the software's failure to enforce string length limits during parsing of the range argument, allowing the attacker to overwrite adjacent heap memory regions.
The operational impact of this vulnerability extends beyond simple denial of service, as it provides a potential pathway for remote code execution and system compromise. Attackers can leverage this flaw to manipulate heap memory layout, potentially leading to arbitrary code execution with the privileges of the affected application. The exploit requires minimal user interaction since it can be triggered through malformed plot commands in gnuplot scripts or interactive sessions. This vulnerability affects systems where gnuplot is used for data visualization, particularly in environments where users might process untrusted data or where gnuplot is integrated into larger applications that accept user input for plotting operations. The attack surface is broad given gnuplot's widespread use in scientific computing, data analysis, and educational environments where users might inadvertently execute malicious plot commands.
Mitigation strategies for CVE-2018-19490 should prioritize immediate patching of affected gnuplot installations to version 5.2.6 or later, which contains the necessary fixes for the buffer overflow vulnerability. System administrators should implement input validation controls that enforce reasonable length limits on range arguments and consider restricting gnuplot execution privileges in multi-user environments. Additional protective measures include deploying heap-based memory protection mechanisms such as stack canaries and address space layout randomization to complicate exploitation attempts. Organizations should also monitor for potential exploitation attempts through network traffic analysis and system logs, as the vulnerability may be used in conjunction with other attack vectors. The remediation aligns with ATT&CK technique T1059.001 for command and scripting interpreter, and T1203 for exploitation for privilege escalation, making comprehensive monitoring and patch management essential defensive measures.