CVE-2020-27792 in GhostScript
Summary
by MITRE • 08/20/2022
A heap-based buffer over write vulnerability was found in GhostScript's lp8000_print_page() function in gdevlp8k.c file. An attacker could trick a user to open a crafted PDF file, triggering the heap buffer overflow that could lead to memory corruption or a denial of service.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 04/30/2025
The vulnerability identified as CVE-2020-27792 represents a critical heap-based buffer overflow within the GhostScript document processing library, specifically affecting the lp8000_print_page() function located in the gdevlp8k.c source file. This flaw resides in the raster image processing components that handle printer device drivers, making it particularly dangerous in environments where PDF files are frequently opened or processed. The vulnerability stems from inadequate bounds checking when handling memory allocation for raster data during print operations, creating a condition where maliciously crafted input can cause the application to write beyond allocated memory boundaries.
The technical exploitation of this vulnerability occurs when a malicious PDF file contains specially crafted raster data that triggers the lp8000_print_page() function during the print process. The buffer overflow manifests as heap corruption when the application attempts to write data beyond the allocated buffer space, potentially overwriting adjacent memory regions including metadata, pointers, or other critical program structures. This type of vulnerability falls under CWE-121 heap-based buffer overflow classification, which is categorized as a memory safety issue that can result in arbitrary code execution or system instability. The attack vector requires user interaction through opening a malicious PDF file, making it a client-side vulnerability that can be delivered via email attachments, web downloads, or other social engineering techniques.
The operational impact of CVE-2020-27792 extends beyond simple denial of service scenarios to potentially enable remote code execution in vulnerable environments. When triggered, the heap corruption can cause the GhostScript application to crash or behave unpredictably, leading to service disruption for end users. More critically, the memory corruption could be leveraged by attackers to manipulate program execution flow, potentially allowing for privilege escalation or arbitrary code execution depending on the system configuration and memory layout. This vulnerability affects various versions of GhostScript and is particularly concerning in enterprise environments where PDF processing is common, as it could be exploited through web browsers, email clients, or document management systems that utilize GhostScript for rendering. The vulnerability aligns with ATT&CK technique T1203 (Exploitation for Client Execution) and T1059 (Command and Scripting Interpreter) as it requires user interaction to execute malicious payloads.
Mitigation strategies for CVE-2020-27792 should prioritize immediate patching of affected GhostScript versions, with administrators monitoring for updates from the upstream project and security vendors. System administrators should implement application whitelisting controls to restrict execution of untrusted PDF processing applications and consider sandboxing PDF viewers to limit potential impact. Network-based protections can include filtering PDF content at network boundaries and implementing strict access controls for document processing systems. Organizations should also conduct vulnerability assessments to identify systems running affected versions of GhostScript and establish monitoring procedures for detecting potential exploitation attempts. The vulnerability demonstrates the importance of memory safety practices in document processing libraries and highlights the need for regular security audits of third-party components used in enterprise document workflows. Additionally, implementing principle of least privilege for PDF processing applications and maintaining up-to-date security patches for all system components remains essential in defending against similar vulnerabilities in the future.