openSUSE releases critical security update for Ghostscript fixing stack-based buffer overflow vulnerabilities CVE-2025-59798 and CVE-2025-59799 in PDF processing. Learn patch instructions and mitigation steps to prevent arbitrary code execution.
Understanding the Ghostscript Security Threat
The openSUSE security team has announced a moderate-rated security update addressing two significant vulnerabilities in Ghostscript, the powerful PostScript and PDF interpreter used across countless Linux systems and applications.
These stack-based buffer overflows (CVE-2025-59798 and CVE-2025-59799) represent a serious threat to systems processing untrusted PDF files, potentially enabling attackers to execute arbitrary code on vulnerable systems.
What makes these vulnerabilities particularly concerning is Ghostscript's widespread integration into document processing pipelines, web applications, and printing systems - often working behind the scenes in tools like ImageMagick and various PDF viewers.
The discovery of these vulnerabilities follows a pattern of memory safety issues in Ghostscript, highlighting the ongoing challenges in securing complex document processing systems against sophisticated exploit attempts .
For organizations relying on openSUSE Linux distributions, understanding these vulnerabilities and applying the provided patches is crucial for maintaining system integrity and security compliance.
This comprehensive analysis provides both technical details for system administrators and practical remediation guidance to help secure your systems against potential exploitation.
Technical Analysis of the Ghostscript Vulnerabilities
CVE-2025-59798: PDF Color Map Stack Buffer Overflow
The first vulnerability, identified as CVE-2025-59798, exists within the pdf_write_cmap function located in devices/vector/gdevpdtw.c. This function handles the writing of color map data structures critical to PDF rendering operations.
The vulnerability manifests as a classical stack-based buffer overflow where the application fails to properly validate the size of data being copied into a fixed-size stack buffer .
In practical terms, when Ghostscript processes a maliciously crafted PDF file containing specially designed color map data, the overflow occurs due to insufficient bounds checking before memory operations.
This type of vulnerability can potentially allow attackers to overwrite adjacent memory regions, including function return addresses and stack frames, potentially leading to arbitrary code execution with the privileges of the Ghostscript process .
The Common Vulnerability Scoring System (CVSS) rates this vulnerability at 4.3 (AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N) according to SUSE, while NVD provides a complementary score of 5.5 (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H), reflecting differences in environmental assessments but consistent moderate severity .
CVE-2025-59799: PDF Destination Coercion Stack Overflow
The second vulnerability, tracked as CVE-2025-59799, resides in the pdfmark_coerce_dest function within devices/vector/gdevpdfm.c.
This function handles the coercion of PDF destination parameters with similar insufficient boundary checks on the size parameter. When processing a PDF containing an overly large size value, the function fails to validate whether the destination buffer has adequate capacity, resulting in a stack-based buffer overflow .
This vulnerability shares similar exploitation characteristics with CVE-2025-59798 but affects a different aspect of PDF processing.
The exploitation prerequisites require that an attacker can supply a malicious PDF file to the vulnerable Ghostscript implementation, which then triggers the overflow condition during destination parameter processing.
Successful exploitation could potentially enable arbitrary code execution, denial of service conditions, or other unauthorized actions on the target system .
Both vulnerabilities follow a concerning pattern of memory safety violations that have plagued Ghostscript historically.
Similar issues were addressed in earlier 2025 updates, including CVE-2025-27835 which involved buffer overflows during glyph-to-Unicode conversion in psi/zbfont.c, and CVE-2025-27836 which concerned print buffer overflows in BJ10V device handling .
Affected Systems and Vulnerability Impact Assessment
Vulnerable openSUSE Distributions
The security update specifically addresses these vulnerabilities in the following openSUSE distributions :
| Affected Distribution | Status | Update Availability |
|---|---|---|
| openSUSE Leap 15.6 | Vulnerable | Patch available |
| Basesystem Module 15-SP6 | Vulnerable | Patch available |
| Basesystem Module 15-SP7 | Vulnerable | Patch available |
Understanding the Attack Vector and Potential Impact
These vulnerabilities pose a significant security risk to systems that process untrusted PDF files, which includes:
Web applications with PDF upload or conversion capabilities
Document management systems that automatically process incoming PDF files
Print servers handling PDF print jobs from multiple users
Email systems with automated PDF preview generation
Cloud services offering PDF conversion or optimization
The exploitation complexity is considered relatively low, as attackers need only craft a malicious PDF file that triggers the overflow conditions when processed by a vulnerable Ghostscript instance.
However, modern system protections such as stack canaries, address space layout randomization (ASLR), and data execution prevention (DEP) would significantly raise the bar for successful code execution exploits .
Despite these mitigations, the vulnerabilities still present a tangible risk of service disruption through denial-of-service attacks, and determined attackers may find ways to bypass protections in specific environments.
The historical context of Ghostscript vulnerabilities demonstrates that sandbox escapes and memory corruption issues have been reliably exploited in the past, as evidenced by CVE-2018-19475 which enabled command execution even in SAFER mode .
Immediate Remediation and Patch Installation Guide
Patch Installation Methods
The openSUSE security team provides multiple remediation pathways to address these vulnerabilities. System administrators should prioritize applying these updates during their next maintenance window .
Primary Update Methods:
YaST Online Update: The recommended graphical method for openSUSE systems with desktop environments
Zypper Patch Command: The preferred terminal-based approach for server systems and headless installations
Product-Specific Patch Commands:
For targeted updates, administrators can run these distribution-specific commands :
openSUSE Leap 15.6:
zypper in -t patch openSUSE-SLE-15.6-2025-4148=1
Basesystem Module 15-SP6:
zypper in -t patch SUSE-SLE-Module-Basesystem-15-SP6-2025-4148=1
Basesystem Module 15-SP7:
zypper in -t patch SUSE-SLE-Module-Basesystem-15-SP7-2025-4148=1
Verification and Validation Procedures
After applying the security update, administrators should:
Verify installed version: Confirm that the Ghostscript package has been updated to version
9.52-150000.211.1or laterValidate functionality: Test PDF processing capabilities to ensure operational continuity
Monitor system logs: Check for any Ghostscript-related errors that might indicate compatibility issues
Document remediation: Record the patch application for compliance and audit purposes
Proactive Security Measures and Defense Strategies
Beyond Patching: Strengthening Your Security Posture
While applying the specific security update is crucial, organizations should consider these additional protective measures to enhance their overall security posture:
Principle of Least Privilege: Ensure Ghostscript processes run with minimal necessary privileges to limit potential impact of successful exploitation
Input Validation: Implement strict validation of all incoming PDF files at application boundaries before passing to Ghostscript
Sandboxing Techniques: Where possible, run Ghostscript operations in isolated containers or virtualized environments
Network Security Controls: Restrict external access to services that utilize Ghostscript for PDF processing
Continuous Monitoring: Deploy security monitoring solutions to detect exploitation attempts through anomalous process behavior or crash reports
Vulnerability Management Program Integration
These Ghostscript vulnerabilities underscore the importance of maintaining a robust vulnerability management program that includes:.
Regular patch assessment: Continuously monitor vendor security announcements through official channels like the openSUSE Security Team .
Dependency mapping: Maintain accurate inventory of all software components and their dependencies, including hidden ones like Ghostscript.
Prioritization framework: Focus remediation efforts on vulnerabilities with active exploitation or significant impact.
Testing protocols: Establish pre-deployment testing procedures for security updates in development environments.
Frequently Asked Questions About the Ghostscript Vulnerabilities
Q1: Are these vulnerabilities being actively exploited in the wild?
A: As of the latest available information, there are no confirmed reports of active exploitation. However, the public disclosure increases the likelihood of exploitation attempts, making prompt patching essential.Q2: Can these vulnerabilities be exploited through web applications?
A: Yes, if a web application uses Ghostscript to process user-uploaded PDF files, it could potentially be exploited by a malicious file upload.Q3: Does the -dSAFER sandbox option provide protection against these vulnerabilities?
A: While -dSAFER restricts certain operations, it does not prevent memory corruption vulnerabilities like these buffer overflows from being triggered .Q4: Are other Linux distributions affected besides openSUSE?
A: Yes, these vulnerabilities affect Ghostscript itself. Distributions like Debian have also released updates addressing these same CVEs .Q5: What is the difference between these vulnerabilities and previous Ghostscript issues?
A: While similar in nature to earlier buffer overflows like CVE-2025-27835, these affect different components specifically within PDF color map and destination handling code .Conclusion
The discovery of CVE-2025-59798 and CVE-2025-59799 in Ghostscript reinforces the critical importance of maintaining current security patches for all system components, even those operating transparently in the background like document processing libraries.
These moderate-severity vulnerabilities present a genuine risk to organizations that process untrusted PDF files, with potential consequences ranging from service disruption to arbitrary code execution.
System administrators should prioritize applying the provided security updates using the zypper patch commands specified for their respective openSUSE distributions.
Additionally, organizations should review their broader security hardening strategies for document processing pipelines, considering implementation of defense-in-depth measures such as input sanitization, privilege reduction, and operational sandboxing.
For ongoing security announcements and technical guidance, subscribe to the official openSUSE security mailing lists and regularly consult the Ghostscript security advisories to stay informed about emerging threats and necessary remediation measures .
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