CVE-2015-5235 in IcedTea-Web
Summary
by MITRE
IcedTea-Web before 1.5.3 and 1.6.x before 1.6.1 does not properly determine the origin of unsigned applets, which allows remote attackers to bypass the approval process or trick users into approving applet execution via a crafted web page.
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Analysis
by VulDB Data Team • 06/20/2022
The vulnerability identified as CVE-2015-5235 affects IcedTea-Web versions prior to 1.5.3 and 1.6.x versions before 1.6.1, representing a critical security flaw in the Java plugin execution environment. This vulnerability stems from improper origin determination mechanisms for unsigned applets, which fundamentally undermines the security model that governs Java applet execution within web browsers. The flaw specifically targets the sandboxing mechanisms that are designed to prevent unsigned applets from executing without explicit user consent, creating a pathway for malicious actors to bypass these critical security controls.
The technical implementation of this vulnerability resides in the way IcedTea-Web handles applet origin validation during the execution process. When a web page attempts to load an unsigned applet, the system should verify the applet's origin against the containing web page's domain to ensure proper security boundaries are maintained. However, the flawed implementation allows attackers to craft web pages that manipulate the origin detection process, effectively tricking the system into believing that unsigned applets originate from trusted sources. This misimplementation creates a scenario where the approval dialog presented to users may not accurately reflect the true origin of the applet, leading to potential user deception and unauthorized execution of malicious code.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it fundamentally compromises the user consent model that forms the cornerstone of Java applet security. Attackers can exploit this weakness to create malicious web pages that appear to originate from legitimate domains, thereby bypassing the security prompts that users typically rely upon to make informed decisions about applet execution. This vulnerability enables a range of malicious activities including but not limited to credential theft, system reconnaissance, and privilege escalation attacks that would otherwise be blocked by proper origin verification. The flaw particularly affects environments where users are prompted to approve applet execution, making it especially dangerous in enterprise settings where users may not be fully aware of the security implications of their decisions.
Security professionals should recognize this vulnerability as a classic example of improper input validation and origin verification, which aligns with CWE-20 - Improper Input Validation and CWE-284 - Improper Access Control. The attack pattern described in the vulnerability corresponds to techniques found in the ATT&CK framework under T1211 - Exploitation for Privilege Escalation and T1059 - Command and Scripting Interpreter, as attackers can leverage this flaw to execute malicious code with elevated privileges. Organizations should prioritize immediate patching of affected IcedTea-Web installations to address this vulnerability, while also implementing additional monitoring measures to detect potential exploitation attempts. The recommended mitigation strategy involves upgrading to IcedTea-Web version 1.5.3 or 1.6.1 and higher, which contain the necessary fixes to properly validate applet origins and maintain the integrity of the security boundary between trusted and untrusted applets. Additionally, administrators should consider implementing network-level controls and user education programs to further reduce the risk of successful exploitation through social engineering techniques that may accompany such attacks.