by Kastro
Paper/Archive/CVE-2025-13476

CVE-2025-13476

Rakuten Viber Rakuten Viber Cloak - Android — Rakuten Viber uses broken or risky cryptographic Algorithm

EPSS 0.4%CVSS 9.8
critical.is priorityof 100
36
CVSS 9.8 (ADP)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 30.7.307 × 206.1No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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

ProductAffectedFixed inSource
Rakuten Viber Cloak - Android25.7.2.0g – < 27.2.0.0g27.2.0.0gCNA
Rakuten Viber Cloak - Windowsv25.6.0.0 – < v27.3.0.0v27.3.0.0CNA

Scores by source

CISA ADP9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

refviber.com/en/downloadrefkb.cert.org/vuls/id/772695