CVE-2004-2535 in Sticker
Summary
by MITRE
The person-to-person secure messaging feature in Sticker before 3.1.0 beta 2 allows remote attackers to post messages to unauthorized private groups by using the group s public encryption key.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 06/29/2018
The vulnerability described in CVE-2004-2535 represents a critical flaw in the access control mechanism of Sticker's person-to-person secure messaging system. This issue affects versions prior to 3.1.0 beta 2 and stems from improper authentication and authorization checks within the secure messaging feature. The flaw specifically targets the group messaging functionality where the system fails to properly verify user permissions before allowing message posting to private groups. This vulnerability creates a significant security gap that allows malicious actors to bypass intended access restrictions and gain unauthorized participation in private communications.
The technical implementation of this vulnerability demonstrates a classic case of insufficient authorization checks, which maps directly to CWE-285 - Improper Authorization. The system incorrectly relies on the group's public encryption key as a means of access control rather than implementing proper user authentication and permission verification. When an attacker possesses a group's public encryption key, they can exploit this weakness to inject messages into private groups without proper authorization. This occurs because the system does not validate whether the sender has legitimate access rights to the target group before processing the message submission. The flaw essentially transforms a secure communication channel into an insecure one where unauthorized parties can manipulate group conversations.
From an operational perspective, this vulnerability poses severe risks to the confidentiality and integrity of private communications within the Sticker platform. Attackers can exploit this weakness to post unauthorized messages to private groups, potentially leading to information disclosure, social engineering attacks, or disruption of group communications. The impact extends beyond simple message posting as it undermines the fundamental security model of private group messaging, which is designed to ensure that only authorized participants can engage in confidential discussions. This vulnerability could enable attackers to spread misinformation, conduct phishing campaigns, or gain access to sensitive information shared within private groups.
The exploitation of this vulnerability aligns with several techniques documented in the MITRE ATT&CK framework, particularly those related to privilege escalation and credential manipulation. Attackers can leverage this weakness to move laterally within the communication system and potentially access other group resources. The vulnerability also represents a failure in the principle of least privilege, where the system grants access based on public key availability rather than verified user credentials. Organizations using affected versions of Sticker should immediately implement mitigations including updating to version 3.1.0 beta 2 or later, implementing additional access control layers, and conducting security audits of group membership and message routing. The fix should address the core authorization logic to ensure that only authenticated users with proper group permissions can post messages, while also implementing proper key management practices to prevent unauthorized key access.