CVE-2018-15542 in Telegram
Summary
by MITRE
** DISPUTED ** An issue was discovered in the org.telegram.messenger application 4.8.11 for Android. The Passcode feature allows authentication bypass via runtime manipulation that forces a certain method's return value to true. In other words, an attacker could authenticate with an arbitrary passcode. NOTE: the vendor indicates that this is not an attack of interest within the context of their threat model, which excludes Android devices on which rooting has occurred.
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Analysis
by VulDB Data Team • 06/18/2024
The vulnerability identified as CVE-2018-15542 represents a critical security flaw in the Telegram messenger application version 4.8.11 for Android platforms. This issue specifically targets the application's passcode authentication mechanism, which is designed to provide an additional layer of security for user accounts and conversations. The vulnerability stems from improper implementation of runtime security checks that should prevent unauthorized access to protected features. According to the vendor's assessment, this weakness is considered not to be a significant threat within their established threat model, as it only affects devices that have been compromised through rooting or similar unauthorized modifications. However, this limitation in the vendor's threat model does not diminish the technical severity of the vulnerability itself.
The technical flaw manifests through runtime manipulation capabilities that allow attackers to alter the behavior of specific methods within the application's code execution flow. This particular vulnerability falls under the category of runtime manipulation attacks, where malicious actors can modify the execution environment to force certain conditional statements to evaluate to true regardless of actual authentication status. The implementation of the passcode verification logic appears to have been designed without adequate protection against dynamic code modification techniques, making it susceptible to manipulation during application runtime. This type of vulnerability is particularly dangerous because it bypasses the fundamental security principle that authentication mechanisms should remain robust against manipulation attempts.
The operational impact of this vulnerability extends beyond simple unauthorized access to account features. An attacker who successfully exploits this weakness could potentially gain access to all conversations, messages, and personal data stored within the Telegram application. The ability to authenticate with arbitrary passcodes undermines the entire security framework that the application's developers intended to establish for protecting user privacy and communication integrity. From a cybersecurity perspective, this vulnerability represents a significant risk to user confidentiality and could enable further exploitation attempts such as message interception, conversation manipulation, or even account takeover scenarios. The vulnerability's classification aligns with CWE-284, which addresses improper access control mechanisms in software applications, and potentially with CWE-94, which covers insufficient control of generation of code.
The vendor's statement that this issue is not considered an attack of interest within their threat model specifically excludes devices that have been rooted or otherwise compromised, suggesting that their security assumptions are based on the premise that users maintain device integrity. This approach reflects a common security strategy where vendors focus their resources on defending against threats that are likely to occur on properly secured devices rather than on compromised systems. However, from a broader security standpoint, this vulnerability demonstrates the importance of implementing robust runtime protections and defensive measures that can withstand manipulation attempts even on compromised devices. The ATT&CK framework would categorize this vulnerability under techniques related to code injection and runtime manipulation, specifically targeting the application's authentication and access control components. Security professionals should consider this vulnerability as part of a broader threat landscape that includes both legitimate security controls and the potential for sophisticated attacks that exploit implementation weaknesses in authentication mechanisms.
Mitigation strategies for this vulnerability should include comprehensive code review processes that specifically examine authentication flow implementations and their susceptibility to runtime manipulation. Developers should implement additional runtime integrity checks that can detect and respond to code modification attempts, potentially through techniques such as code signing verification, integrity monitoring, or anti-debugging measures. The application should also incorporate multiple layers of authentication verification that cannot be easily bypassed through simple method return value manipulation. Additionally, regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in authentication systems, particularly those that rely on single-point verification mechanisms. Users should be educated about the importance of maintaining device integrity and avoiding rooting or jailbreaking their devices, as these modifications can expose them to vulnerabilities like CVE-2018-15542 and other similar runtime manipulation attacks.