CVE-2020-18081 in SEMCMS
Summary
by MITRE • 12/17/2021
The checkuser function of SEMCMS 3.8 was discovered to contain a vulnerability which allows attackers to obtain the password in plaintext through a SQL query.
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Analysis
by VulDB Data Team • 12/24/2021
The vulnerability identified as CVE-2020-18081 resides within the checkuser function of SEMCMS version 3.8, representing a critical security flaw that undermines the application's authentication mechanisms. This issue stems from improper input validation and sanitization within the user verification process, creating an avenue for attackers to exploit the system's database interaction routines. The flaw specifically manifests when the application processes user authentication requests, allowing malicious actors to craft SQL queries that bypass normal authentication procedures and directly access sensitive user information.
The technical implementation of this vulnerability demonstrates a classic SQL injection weakness where the checkuser function fails to properly escape or parameterize user inputs before incorporating them into database queries. When an attacker submits specially crafted credentials or parameters to the authentication endpoint, the application's insufficient input filtering allows SQL syntax manipulation that can be leveraged to extract plaintext passwords from the database. This represents a direct violation of security principle 12 from the OWASP Top Ten 2017, which addresses injection flaws that can lead to unauthorized data access and system compromise. The vulnerability operates at the application layer and can be classified under CWE-89, SQL Injection, which is a well-documented weakness in software development practices.
The operational impact of this vulnerability extends beyond simple credential theft, as it provides attackers with unrestricted access to user accounts and potentially sensitive system information. Once an attacker successfully exploits this flaw, they gain the ability to authenticate as any user within the system without requiring legitimate credentials, effectively compromising the entire user base. This vulnerability can be exploited using standard penetration testing tools and techniques that automate SQL injection attacks, making it particularly dangerous in environments where the application is publicly accessible. The plaintext password exposure represents a severe risk to user security, as these credentials can be immediately used to access other systems where users may have reused passwords, creating cascading security failures.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term security improvements within the SEMCMS application. The primary fix involves implementing proper parameterized queries or prepared statements within the checkuser function to ensure that all user inputs are properly escaped and treated as data rather than executable code. Additionally, the application should enforce strict input validation and sanitization routines that filter out potentially malicious SQL syntax from all authentication-related inputs. Organizations should also implement comprehensive logging and monitoring of authentication attempts to detect suspicious activities that may indicate exploitation attempts. The remediation process should follow the principle of least privilege by ensuring that database accounts used by the application have minimal required permissions, preventing attackers from accessing additional sensitive data even if they successfully exploit the vulnerability. This vulnerability aligns with ATT&CK technique T1190, Exploit Public-Facing Application, and T1078, Valid Accounts, as it allows adversaries to leverage compromised authentication mechanisms to establish persistent access to target systems.