CVE-2018-3849 in CFITSIO
Summary
by MITRE
In the ffghtb function in NASA CFITSIO 3.42, specially crafted images parsed via the library can cause a stack-based buffer overflow overwriting arbitrary data. An attacker can deliver an FIT image to trigger this vulnerability and potentially gain code execution.
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Analysis
by VulDB Data Team • 02/28/2023
The vulnerability identified as CVE-2018-3849 resides within the ffghtb function of NASA's CFITSIO library version 3.42, representing a critical stack-based buffer overflow flaw that poses significant security risks to systems processing FITS (Flexible Image Transport System) formatted image data. This library serves as a widely-used standard for astronomical data processing and storage, making the vulnerability particularly concerning given its potential for widespread impact across scientific and research computing environments. The flaw specifically manifests when parsing specially crafted FITS images that contain malformed header data structures, creating conditions where buffer boundaries are exceeded during memory operations.
The technical execution of this vulnerability involves a classic stack-based buffer overflow scenario where insufficient input validation occurs within the ffghtb function. When the library processes FITS headers containing maliciously constructed data, the function fails to properly bounds-check the size of incoming data before copying it into fixed-size stack buffers. This allows an attacker to overwrite adjacent memory locations including return addresses, function pointers, and other critical control data structures. The vulnerability is particularly dangerous because it operates within a library that is frequently used in mission-critical applications, including space exploration projects and astronomical research facilities where system reliability and security are paramount. The overflow can potentially be exploited to execute arbitrary code with the privileges of the process running the vulnerable application.
The operational impact of CVE-2018-3849 extends beyond simple denial of service scenarios, as successful exploitation could enable attackers to gain complete control over affected systems. This risk is amplified by the widespread adoption of CFITSIO across various scientific computing platforms and astronomical data processing pipelines. Attackers could leverage this vulnerability to deliver malicious FITS files through various attack vectors including email attachments, web downloads, or compromised data repositories. The exploitation process would require careful crafting of the malicious FITS file to ensure proper overflow conditions are met while maintaining the file's apparent legitimacy to avoid detection. This vulnerability directly maps to CWE-121 Stack-based Buffer Overflow and aligns with ATT&CK techniques involving code injection and privilege escalation. The attack surface is particularly broad given that CFITSIO is used in numerous applications including astronomical data analysis software, scientific data management systems, and research computing environments where untrusted FITS data is commonly processed.
Mitigation strategies for CVE-2018-3849 should prioritize immediate patching of affected CFITSIO installations to version 3.43 or later, which contains the necessary fixes for the buffer overflow conditions. System administrators should implement strict input validation policies for all FITS data processing pipelines, including mandatory file format verification and size constraints before data ingestion. Network-level protections such as content filtering and sandboxing mechanisms can provide additional layers of defense against malicious FITS file delivery. Organizations should also consider implementing runtime protections including stack canaries and address space layout randomization to make exploitation more difficult. Regular security assessments of scientific computing environments and vulnerability scanning of deployed CFITSIO versions should be conducted to ensure ongoing protection. The vulnerability demonstrates the critical importance of secure coding practices in scientific software libraries and highlights the need for comprehensive security testing in mission-critical applications where buffer overflows can have catastrophic consequences.