CVE-2025-13476: Rakuten Viber uses broken or risky cryptographic Algorithm
Rakuten Viber Cloak mode in Android v25.7.2.0g and Windows v25.6.0.0–v25.8.1.0 uses a static and predictable TLS ClientHello fingerprint lacking extension diversity, allowing Deep Packet Inspection (DPI) systems to trivially identify and block proxy traffic, undermining censorship circumvention. (CWE-327)
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2025-13476?
CVE-2025-13476 has a medium severity rating due to its use of a predictable TLS ClientHello fingerprint that can be easily identified by DPI systems.
How do I fix CVE-2025-13476?
To mitigate CVE-2025-13476, update Rakuten Viber to version 25.8.1.0 or later, which includes fixes for the cryptographic vulnerabilities.
Which versions of Viber are affected by CVE-2025-13476?
Viber versions 25.7.2.0g and 25.6.0.0 to 25.8.1.0 are affected by CVE-2025-13476.
What types of attacks could exploit CVE-2025-13476?
CVE-2025-13476 could be exploited by attackers using Deep Packet Inspection techniques to analyze and potentially manipulate traffic.
Can CVE-2025-13476 impact user privacy?
Yes, CVE-2025-13476 can impact user privacy by allowing third parties to easily identify and monitor Viber traffic.