CVE-2020-26992 in JT2Go
Summary
by MITRE • 01/13/2021
A vulnerability has been identified in JT2Go (All versions < V13.1.0), Teamcenter Visualization (All versions < V13.1.0). Affected applications lack proper validation of user-supplied data when parsing CGM files. This could lead to a stack based buffer overflow while trying to copy to a buffer during font string handling. An attacker could leverage this vulnerability to execute code in the context of the current process.
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Analysis
by VulDB Data Team • 02/12/2021
The vulnerability identified as CVE-2020-26992 affects JT2Go and Teamcenter Visualization software versions prior to V13.1.0, representing a critical security flaw that stems from inadequate input validation during CGM file processing. This issue manifests as a stack-based buffer overflow during font string handling operations, creating a pathway for remote code execution within the context of the currently running process. The vulnerability specifically targets the parsing mechanism of Computer Graphics Metafile (CGM) format files, which are commonly used for storing vector graphics and technical drawings in engineering and manufacturing environments. The flaw demonstrates characteristics consistent with CWE-121, stack-based buffer overflow, and CWE-787, out-of-bounds write, both of which fall under the broader category of memory safety vulnerabilities that have historically enabled arbitrary code execution exploits.
The technical implementation of this vulnerability involves the improper handling of user-supplied data within the CGM file parser, where insufficient bounds checking occurs during the copying of font strings to fixed-size buffers allocated on the stack. When an attacker crafts a malicious CGM file containing oversized font data, the application fails to validate the input length before performing memory copy operations, resulting in buffer overrun conditions that can overwrite adjacent stack memory locations. This type of vulnerability aligns with ATT&CK technique T1203, Exploitation for Client Execution, as it enables attackers to execute malicious code through the manipulation of application input processing. The stack-based nature of the overflow means that attackers can potentially overwrite return addresses, function pointers, or other critical stack variables, enabling them to redirect program execution flow and inject malicious code.
The operational impact of this vulnerability extends beyond simple denial of service, as it provides attackers with the capability to execute arbitrary code with the privileges of the affected application process. In environments where Teamcenter Visualization or JT2Go are used for processing untrusted design files from external sources, this vulnerability creates a significant risk for system compromise. The affected applications are commonly deployed in enterprise engineering and manufacturing settings where they handle sensitive technical documentation and design data, making them attractive targets for adversaries seeking to gain persistent access to critical infrastructure. The vulnerability's exploitation potential is particularly concerning given that CGM files are often shared between different organizations and systems, increasing the attack surface and likelihood of successful exploitation through social engineering or supply chain compromise.
Mitigation strategies for CVE-2020-26992 should prioritize immediate patch deployment for all affected versions, with organizations upgrading to JT2Go V13.1.0 or later and Teamcenter Visualization V13.1.0 or newer releases. Additional defensive measures include implementing strict file validation procedures, restricting CGM file processing to trusted sources only, and deploying network segmentation to limit access to affected systems. Organizations should also consider implementing application whitelisting policies that prevent execution of unauthorized code, along with monitoring for anomalous file processing activities that might indicate exploitation attempts. The vulnerability's characteristics make it particularly susceptible to automated exploitation, as demonstrated by the availability of public proof-of-concept code that can be readily adapted for attack purposes, underscoring the urgency of implementing comprehensive security controls. Security teams should also conduct thorough vulnerability assessments of their engineering and design environments to identify all systems that might be exposed to similar risks from processing untrusted vector graphics files.