CVE-2019-14869 in Ghostscript
Summary
by MITRE
A flaw was found in all versions of ghostscript 9.x before 9.28, where the `.charkeys` procedure, where it did not properly secure its privileged calls, enabling scripts to bypass `-dSAFER` restrictions. An attacker could abuse this flaw by creating a specially crafted PostScript file that could escalate privileges within the Ghostscript and access files outside of restricted areas or execute commands.
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Analysis
by VulDB Data Team • 06/17/2025
The vulnerability identified as CVE-2019-14869 represents a critical security flaw in the Ghostscript 9.x software family affecting versions prior to 9.28. This issue resides within the `.charkeys` procedure implementation and fundamentally undermines the security model designed to protect users from malicious PostScript content. The flaw demonstrates a classic privilege escalation vulnerability where legitimate security mechanisms are bypassed through improper handling of privileged operations within the interpreter.
The technical nature of this vulnerability stems from insufficient privilege checking within the `.charkeys` procedure, which is a core component of Ghostscript's PostScript interpreter. This procedure is responsible for handling character key mappings and typically operates within restricted contexts. However, the flaw allows unprivileged script execution to bypass the `-dSAFER` security parameter that normally limits file system access and command execution capabilities. The vulnerability specifically affects how the interpreter handles privileged calls during character key processing, creating an attack vector where malicious code can escalate privileges without proper authorization checks.
The operational impact of CVE-2019-14869 extends beyond simple privilege escalation to encompass complete system compromise potential. Attackers can craft malicious PostScript files that exploit this flaw to access restricted file systems, execute arbitrary commands, and potentially gain unauthorized access to sensitive data. This vulnerability particularly affects environments where Ghostscript is used for document processing, image conversion, or as part of larger applications that handle untrusted input. The security implications are severe because Ghostscript is widely deployed across enterprise environments, web applications, and document management systems, making this vulnerability particularly dangerous.
From a cybersecurity perspective, this vulnerability aligns with CWE-284 (Improper Access Control) and represents a privilege escalation flaw that enables attackers to bypass security controls established by the `-dSAFER` parameter. The ATT&CK framework categorizes this under privilege escalation techniques, specifically targeting the execution of malicious code through interpreter vulnerabilities. Organizations using Ghostscript in production environments face significant risk exposure, particularly those that process untrusted document formats or serve as document conversion services. The vulnerability demonstrates how interpreter-level flaws can undermine application security models and create persistent attack vectors that persist across multiple system components.
Mitigation strategies for CVE-2019-14869 require immediate software updates to Ghostscript 9.28 or later versions where the vulnerability has been patched. Organizations should also implement additional security measures including restricting file system access for Ghostscript processes, deploying network segmentation to limit exposure, and monitoring for suspicious PostScript file processing activities. Regular security assessments should verify that all Ghostscript installations are properly patched and that security parameters are correctly enforced. System administrators should also consider implementing sandboxing techniques and access control lists to further reduce the potential impact of such vulnerabilities in the event of exploitation attempts.