CVE-2021-20105 in Machform
Summary
by MITRE • 06/30/2021
Machform prior to version 16 is vulnerable to an open redirect in Safari_init.php due to an improperly sanitized 'ref' parameter.
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Analysis
by VulDB Data Team • 07/03/2021
The vulnerability identified as CVE-2021-20105 affects Machform versions prior to 16, specifically within the Safari_init.php component where an open redirect flaw exists due to inadequate sanitization of the 'ref' parameter. This issue represents a classic security weakness that can be exploited to manipulate user navigation to malicious destinations while maintaining the appearance of legitimate web traffic. The vulnerability stems from the application's failure to properly validate and sanitize user-supplied input before using it in redirect operations, creating an opportunity for attackers to craft malicious URLs that could deceive users into visiting harmful websites.
The technical implementation of this flaw involves the application's handling of the 'ref' parameter which is typically used to determine the destination page after authentication or other user actions. When Machform processes this parameter without adequate input validation, it allows attackers to inject arbitrary URLs that bypass normal security checks. This creates a pathway for attackers to construct phishing campaigns where victims might be redirected to fake login pages or sites designed to capture credentials and sensitive information. The vulnerability specifically impacts Safari browsers due to how Safari handles redirect operations, though similar issues could potentially affect other browsers that process the same parameter in comparable ways.
From an operational perspective, this open redirect vulnerability significantly increases the risk of social engineering attacks and credential theft. Attackers can exploit this flaw by crafting malicious links that appear to originate from legitimate Machform installations, making it difficult for users to distinguish between genuine and malicious redirects. The impact extends beyond simple phishing as this vulnerability could enable more sophisticated attacks including session hijacking, data exfiltration, and the deployment of additional malware. Security researchers have noted that such open redirect vulnerabilities are particularly dangerous because they can be chained with other attacks to create more complex and effective exploitation scenarios.
Mitigation strategies for this vulnerability should include immediate patching to version 16 or later where the sanitization issue has been addressed. Organizations should implement proper input validation and sanitization techniques that ensure all user-supplied parameters are thoroughly checked before being used in redirect operations. The fix should include strict validation of URLs to ensure they conform to expected patterns and reject any input that appears suspicious or attempts to redirect to external domains. Additionally, implementing web application firewalls with rules to detect and block suspicious redirect patterns can provide an additional layer of protection. Security teams should also conduct regular penetration testing to identify similar vulnerabilities in other applications and ensure proper security controls are in place to prevent unauthorized redirects. This vulnerability aligns with CWE-601 Open Redirect vulnerability classification and can be mapped to ATT&CK technique T1566.001 Phishing via Social Media within the initial access phase of the attack lifecycle.