CVE-2001-1022 in groff
Summary
by MITRE
Format string vulnerability in pic utility in groff 1.16.1 and other versions, and jgroff before 1.15, allows remote attackers to bypass the -S option and execute arbitrary commands via format string specifiers in the plot command.
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Analysis
by VulDB Data Team • 09/30/2025
The vulnerability described in CVE-2001-1022 represents a critical format string flaw within the pic utility component of the groff document formatting system. This issue affects groff versions 1.16.1 and earlier, as well as jgroff versions prior to 1.15, creating a significant security risk that can be exploited remotely. The pic utility serves as a preprocessor for creating diagrams and plots within troff documents, making it an integral part of the document preparation pipeline for many Unix-based systems. The vulnerability specifically manifests in how the utility handles format string specifiers within the plot command, allowing attackers to craft malicious input that can manipulate the program's execution flow.
The technical nature of this vulnerability stems from improper input validation and handling within the pic utility's parsing logic. When the utility processes plot commands containing format string specifiers, it fails to properly sanitize user input before passing it to functions that perform formatted output operations. This allows attackers to inject format specifiers such as %n, %s, or other malicious sequences that can cause the program to read from or write to arbitrary memory locations. The flaw enables attackers to bypass the intended security mechanism represented by the -S option, which should normally restrict command execution. This bypass capability transforms what should be a controlled environment into one where arbitrary code execution becomes possible through carefully crafted input.
The operational impact of this vulnerability extends beyond simple command execution, as it fundamentally compromises the integrity of systems that rely on groff for document processing. Attackers can leverage this weakness to execute arbitrary commands with the privileges of the user running the pic utility, potentially leading to complete system compromise if the utility runs with elevated permissions. The vulnerability is particularly dangerous in environments where users can submit documents for processing, such as web-based document conversion services, collaborative editing platforms, or automated document generation systems. The remote exploit capability means that attackers do not need physical access to the system, making the vulnerability accessible from any network location where the affected software is deployed.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term security hardening. The primary solution involves upgrading to patched versions of groff and jgroff where the format string vulnerability has been resolved through proper input validation and sanitization. System administrators should also implement input filtering mechanisms that prevent format string specifiers from being processed in plot commands, particularly in environments where untrusted input is accepted. The vulnerability aligns with CWE-134, which specifically addresses format string vulnerabilities where format strings are constructed from user-controlled data. From an ATT&CK framework perspective, this vulnerability maps to techniques involving command and control through arbitrary code execution, potentially enabling lateral movement and privilege escalation within compromised systems. Organizations should also consider implementing runtime protections such as stack canaries and address space layout randomization to mitigate potential exploitation attempts, while maintaining comprehensive monitoring for suspicious command execution patterns that might indicate exploitation attempts.