CVE-2025-13476 describes a vulnerability in Rakuten Viber's Cloak mode for Android (v25.7.2.0g) and Windows (v25.6.0.0–v25.8.1.0). The issue stems from the use of a static and predictable TLS ClientHello fingerprint, which lacks sufficient extension diversity. This design flaw allows Deep Packet Inspection (DPI) systems to easily identify and block Viber's proxy traffic, effectively undermining its censorship circumvention capabilities. While no CVSS score is provided, the impact is primarily on the user's ability to bypass censorship, rather than direct system compromise. There is no evidence of active exploitation, public exploit code, or significant community discussion surrounding this vulnerability.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
>= 25.6.0, <= 25.8.1.0CPE matchmatch criteria | cpe:2.3:a:rakuten:viber:*:*:*:*:*:windows:*:* | ||
9.3.0.6CPE matchmatch criteria | cpe:2.3:a:rakuten:viber:9.3.0.6:25.7.2.0g:*:*:*:android:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.3 Bluesky, 0.3 Mastodon, and 2.4 GitHub mentions.
No media coverage found for this CVE.
The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.
Remediation records are not available for this CVE.