CVE-2020-37012 in Tea LaTex
Summary
by MITRE • 01/29/2026
Tea LaTex 1.0 contains a remote code execution vulnerability that allows unauthenticated attackers to execute arbitrary shell commands through the /api.php endpoint. Attackers can craft a malicious LaTeX payload with shell commands that are executed when processed by the application's tex2png API action.
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Analysis
by VulDB Data Team • 01/29/2026
The vulnerability identified as CVE-2020-37012 affects Tea LaTex version 1.0 and represents a critical remote code execution flaw that exposes the application to unauthenticated attack vectors. This vulnerability resides within the application's API endpoint structure, specifically targeting the /api.php interface where malicious payloads can be injected and subsequently executed. The flaw enables attackers to bypass authentication mechanisms entirely, allowing direct exploitation of the underlying system without requiring valid credentials or privileged access. The vulnerability's severity stems from its ability to execute arbitrary shell commands on the target system, effectively granting attackers full control over the affected server environment. The attack surface is particularly concerning as it leverages the application's legitimate tex2png API functionality to process user-supplied content, making the exploitation appear as normal application behavior.
The technical root cause of this vulnerability lies in improper input validation and sanitization within the LaTeX processing pipeline. When users submit LaTeX content through the /api.php endpoint, the application fails to adequately sanitize or validate the incoming data before processing it through the tex2png conversion function. This insufficient validation creates a path for command injection attacks where attackers can embed shell commands within their LaTeX payload. The vulnerability aligns with CWE-77 and CWE-94 categories, specifically addressing improper input validation and code injection flaws that enable arbitrary code execution. The flaw operates at the intersection of application logic and system command execution, where user-controlled data flows directly into system shell invocations without proper contextual escaping or validation. This design flaw allows attackers to manipulate the processing flow by embedding malicious commands that are then executed in the context of the web server's privileges.
The operational impact of this vulnerability extends beyond simple code execution to encompass complete system compromise and potential lateral movement within network environments. An attacker exploiting this vulnerability can execute commands with the privileges of the web server process, potentially leading to data exfiltration, system enumeration, or deployment of additional malicious tools. The unauthenticated nature of the attack means that any external party can exploit this flaw without requiring prior access or credentials, making it particularly dangerous in publicly accessible environments. Organizations running Tea LaTex 1.0 are exposed to immediate risk of unauthorized access, data breaches, and potential use as a foothold for further attacks within their infrastructure. The vulnerability can be leveraged to establish persistent access, create backdoors, or perform reconnaissance activities that could compromise the broader network security posture. This type of vulnerability directly maps to ATT&CK techniques involving command and control, privilege escalation, and initial access through web application attacks.
Mitigation strategies for CVE-2020-37012 require immediate action to address the core input validation deficiencies within the application's API processing. Organizations should implement comprehensive input sanitization measures that prevent shell command injection by escaping or removing dangerous characters from user-supplied LaTeX content. The most effective immediate solution involves patching the application to properly validate and sanitize all input data before processing it through the tex2png conversion function. System administrators should also consider implementing network-level restrictions to limit access to the vulnerable /api.php endpoint and monitor for suspicious API requests. Additional protective measures include deploying web application firewalls to detect and block malicious payload patterns, implementing least privilege principles for web server accounts, and establishing proper logging and monitoring of API endpoint activities. Regular security assessments and input validation reviews should be conducted to prevent similar vulnerabilities from emerging in other application components. Organizations should also consider migrating to patched versions of Tea LaTex or implementing compensating controls that isolate the vulnerable functionality from critical system resources. The vulnerability demonstrates the importance of secure coding practices and proper input validation as fundamental security controls that must be implemented at every level of application development.