Rakuten Viber Cloak 25.6.0.0/25.7.2.0g/25.8.1.0 risky encryption

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.7$0-$5k0.00

Summaryinfo

A vulnerability was found in Rakuten Viber Cloak 25.6.0.0/25.7.2.0g/25.8.1.0. It has been rated as problematic. The affected element is an unknown function. The manipulation leads to risky encryption. This vulnerability is listed as CVE-2025-13476. The attack may be initiated remotely. There is no available exploit. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Rakuten Viber Cloak 25.6.0.0/25.7.2.0g/25.8.1.0 and classified as problematic. This issue affects an unknown function. The manipulation with an unknown input leads to a risky encryption vulnerability. Using CWE to declare the problem leads to CWE-327. The product uses a broken or risky cryptographic algorithm or protocol. Impacted is confidentiality. The summary by CVE is:

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)

It is possible to read the advisory at viber.com. The identification of this vulnerability is CVE-2025-13476 since 11/20/2025. The exploitation is known to be difficult. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1600 according to MITRE ATT&CK.

Upgrading to version 27.2.0.0g eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2025-208314). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.7
VulDB Meta Temp Score: 6.7

VulDB Base Score: 3.7
VulDB Temp Score: 3.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

ADP CISA Base Score: 9.8
ADP CISA Vector: 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Risky encryption
CWE: CWE-327 / CWE-310
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Cloak 27.2.0.0g

Timelineinfo

11/20/2025 CVE reserved
03/05/2026 +105 days Advisory disclosed
03/05/2026 +0 days VulDB entry created
03/11/2026 +6 days VulDB entry last update

Sourcesinfo

Advisory: viber.com
Status: Confirmed

CVE: CVE-2025-13476 (🔒)
GCVE (CVE): GCVE-0-2025-13476
GCVE (VulDB): GCVE-100-349223
EUVD: 🔒

Entryinfo

Created: 03/05/2026 19:38
Updated: 03/11/2026 21:54
Changes: 03/05/2026 19:38 (54), 03/06/2026 00:46 (1), 03/07/2026 22:50 (11), 03/11/2026 21:54 (1)
Complete: 🔍
Cache ID: 216:FA7:103

Be aware that VulDB is the high quality source for vulnerability data.

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