CVE-2026-55977 in Pro
Summary
by MITRE • 07/28/2026
Successful exploitation of this vulnerability could allow an attacker with local network access to bypass the application's rate-limiting mechanism, enabling brute-forcing of the screen-sharing code and potentially displaying harmful content on the affected screen.
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Analysis
by VulDB Data Team • 07/28/2026
This vulnerability represents a critical security flaw that undermines the fundamental integrity of application access controls through improper rate-limiting implementation. The weakness allows attackers with local network privileges to circumvent protective mechanisms designed to prevent unauthorized access attempts, specifically targeting screen-sharing functionality that serves as a gateway to potentially harmful content delivery. Such a vulnerability directly impacts the confidentiality and integrity of user sessions by enabling unauthorized code brute-forcing attempts that could lead to malicious screen content display. The exploitation requires only local network access, making it particularly dangerous as it can be leveraged from within the same network segment without requiring physical presence or elevated privileges. This type of vulnerability falls under the category of inadequate input validation and access control mechanisms, creating a pathway for attackers to systematically test screen-sharing codes through automated brute-force methods. The operational impact extends beyond simple unauthorized access to include potential data exposure, malicious content injection, and compromise of user privacy during screen sharing sessions.
The technical implementation flaw stems from insufficient rate-limiting enforcement that fails to properly track and restrict consecutive access attempts within the screen-sharing authentication process. Attackers can exploit this by rapidly submitting multiple code guesses without triggering protective mechanisms that should normally delay or block further attempts. This represents a classic case of weak account lockout mechanisms combined with inadequate session management controls, allowing for automated attack vectors that bypass standard security measures. The vulnerability creates a persistent threat surface where attackers can maintain continuous access attempts while avoiding detection through traditional rate-limiting enforcement. From an industry standards perspective, this aligns with CWE-307 which addresses improper restriction of excessive authentication attempts, and specifically relates to the broader category of insufficient logging and monitoring that enables such attacks to proceed undetected.
The operational consequences of this vulnerability extend into multiple security domains including user privacy protection, data integrity maintenance, and system availability. Screen-sharing applications typically handle sensitive information and may be used in corporate environments where unauthorized access could lead to intellectual property theft or confidential communication interception. The ability to display harmful content on affected screens creates additional risk vectors for social engineering attacks and malware delivery mechanisms that can exploit user trust in legitimate screen sharing applications. This vulnerability also opens pathways for more sophisticated attacks including privilege escalation attempts where initial unauthorized access leads to broader system compromise, as documented in various ATT&CK framework techniques related to credential access and execution through legitimate user processes.
Effective mitigation strategies must address both the immediate rate-limiting implementation flaws and broader access control mechanisms. Organizations should implement robust exponential backoff algorithms combined with account lockout procedures that prevent automated brute-force attempts while maintaining usability for legitimate users. Network-level controls including firewall rules and intrusion detection systems can help identify and block suspicious traffic patterns associated with rapid authentication attempts. Regular monitoring of screen-sharing application logs becomes critical for detecting unusual access patterns and potential exploitation attempts. Additionally, implementing multi-factor authentication mechanisms and session timeout controls provides layered protection that reduces the overall attack surface even if rate-limiting mechanisms are bypassed. Security awareness training for users regarding the risks of unauthorized screen sharing access further complements technical controls in establishing comprehensive defense-in-depth strategies against such vulnerabilities.