CVE-2017-11714 in Ghostscript
Summary
by MITRE
psi/ztoken.c in Artifex Ghostscript 9.21 mishandles references to the scanner state structure, which allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact via a crafted PostScript document, related to an out-of-bounds read in the igc_reloc_struct_ptr function in psi/igc.c.
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Analysis
by VulDB Data Team • 12/14/2022
The vulnerability identified as CVE-2017-11714 represents a critical memory safety issue within the Ghostscript document processing library developed by Artifex. This flaw exists in the psi/ztoken.c component and specifically concerns how the software handles references to the scanner state structure during PostScript document parsing operations. The vulnerability manifests when processing maliciously crafted PostScript files that exploit improper memory management during the parsing phase, creating conditions that can lead to application instability and potential system compromise.
The technical root cause of this vulnerability stems from an out-of-bounds read condition within the igc_reloc_struct_ptr function located in psi/igc.c. This function processes structure pointers during the interpretation of PostScript code, but fails to properly validate the bounds of memory access operations. When a crafted PostScript document contains malformed references to scanner state structures, the software attempts to access memory locations beyond the allocated buffer boundaries, resulting in unpredictable behavior. This memory access violation can trigger application crashes, system instability, and potentially provide attackers with opportunities for more sophisticated exploitation techniques. The vulnerability falls under the CWE-125 Out-of-bounds Read classification, which represents a fundamental memory safety issue where programs access memory outside the intended bounds of allocated buffers.
The operational impact of this vulnerability extends beyond simple denial of service conditions, as demonstrated by the unspecified other impacts mentioned in the CVE description. Remote attackers can leverage this flaw to cause application crashes that may result in complete system unavailability, particularly in environments where Ghostscript serves as a core component for document processing. The vulnerability affects systems that process untrusted PostScript content, making it particularly dangerous in web applications, print servers, and document conversion services that handle user-uploaded files. Attackers could potentially exploit this weakness to cause persistent service disruptions, leading to business continuity issues and potential financial losses. The vulnerability's remote exploitability means that malicious actors can trigger the condition without physical access to the target system, making it a significant concern for networked environments.
Mitigation strategies for CVE-2017-11714 should prioritize immediate patching of affected Ghostscript installations to version 9.22 or later, where the memory handling issues have been addressed through improved bounds checking and memory validation procedures. Organizations should implement robust input validation measures for all PostScript content, including sandboxing mechanisms that isolate document processing operations from core system resources. Network administrators should consider implementing content filtering solutions that can identify and block suspicious PostScript files before they reach processing systems. Security monitoring should include detection of abnormal application behavior patterns that may indicate exploitation attempts. From an ATT&CK framework perspective, this vulnerability aligns with techniques involving privilege escalation and denial of service, as attackers can leverage the out-of-bounds read to disrupt system operations and potentially gain further access to compromised systems through subsequent exploitation phases. Organizations should also consider implementing automated vulnerability scanning processes to identify unpatched systems and ensure comprehensive coverage of all affected components within their infrastructure.