Fortinet FortiMail up to 6.2.9/6.4.4 weak prng

CVSS Meta Temp Score
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CTI Interest Score
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5.5$0-$5k0.00

Summaryinfo

A vulnerability was found in Fortinet FortiMail up to 6.2.9/6.4.4. It has been rated as problematic. This vulnerability affects unknown code. This manipulation causes weak prng. This vulnerability appears as CVE-2021-26091. The attack may be initiated remotely. There is no available exploit. Upgrading the affected component is advised.

Detailsinfo

A vulnerability classified as problematic was found in Fortinet FortiMail up to 6.2.9/6.4.4. Affected by this vulnerability is an unknown function. The manipulation with an unknown input leads to a weak prng vulnerability. The CWE definition for the vulnerability is CWE-338. The product uses a Pseudo-Random Number Generator (PRNG) in a security context, but the PRNG's algorithm is not cryptographically strong. As an impact it is known to affect confidentiality. The summary by CVE is:

A use of a cryptographically weak pseudo-random number generator vulnerability in the authenticator of the Identity Based Encryption service of FortiMail 6.4.0 through 6.4.4, and 6.2.0 through 6.2.7 may allow an unauthenticated attacker to infer parts of users authentication tokens and reset their credentials.

The advisory is shared at fortiguard.com. This vulnerability is known as CVE-2021-26091 since 01/25/2021. The exploitation appears to be difficult. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1600.001 for this issue.

Upgrading eliminates this vulnerability.

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Productinfo

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.6
VulDB Meta Temp Score: 5.5

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

CNA Base Score: 7.5
CNA Vector (fortinet): 🔍

CVSSv2info

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

Exploitinginfo

Class: Weak prng
CWE: CWE-338 / CWE-331 / CWE-330
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: 🔍

Timelineinfo

01/25/2021 🔍
03/24/2025 +1519 days 🔍
03/24/2025 +0 days 🔍
07/23/2025 +121 days 🔍

Sourcesinfo

Vendor: fortinet.com

Advisory: FG-IR-21-031
Status: Confirmed

CVE: CVE-2021-26091 (🔍)
GCVE (CVE): GCVE-0-2021-26091
GCVE (VulDB): GCVE-100-300853

Entryinfo

Created: 03/24/2025 17:33
Updated: 07/23/2025 20:06
Changes: 03/24/2025 17:33 (63), 07/23/2025 20:06 (1)
Complete: 🔍
Cache ID: 216::103

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