CVE-2021-41030: An authentication bypass by capture-replay vulnerability [CWE-294] in FortiClient EMS versions 7.0.1 and below and 6.4.4 and below may allow an unauthenticated…

PriorityP264critical9.1CVSS 3.1

AVNACLPRNUINSUCHIHAN

EPSS

0.95%

57.2th percentile

An authentication bypass by capture-replay vulnerability [CWE-294] in FortiClient EMS versions 7.0.1 and below and 6.4.4 and below may allow an unauthenticated attacker to impersonate an existing user by intercepting and re-using valid SAML authentication messages.

Affected

7 ranges

Vendor	Product	Version range	Fixed in
fortinet	forticlient	—	—
fortinet	forticlient_enterprise_management_server	—	—
fortinet	forticlient_enterprise_management_server	—	—
fortinet	forticlient_enterprise_management_server	6.2.0 – 6.2.9	—
fortinet	forticlient_enterprise_management_server	6.4.0 – 6.4.4	—
fortinet	forticliententerprisemanagementserver	—	—
fortinet	fortinet_forticlientems	—	—

Detection & IOCsextracted from sources · hover to see the quote

→Monitor for replayed SAML authentication messages — an attacker may re-submit a previously captured valid SAML assertion to impersonate a legitimate user against FortiClient EMS ↗
→Flag authentication sessions where the same SAML assertion/token is presented more than once (replay detection), particularly against FortiClient EMS endpoints ↗

·Affected versions are FortiClient EMS 7.0.1 and below, and 6.4.4 and below — ensure patched versions are deployed to remediate the SAML replay attack surface ↗
·The vulnerability is classified CWE-294 (Authentication Bypass by Capture-Replay); SAML configurations lacking assertion replay prevention (e.g., missing InResponseTo validation or assertion lifetime enforcement) are at highest risk ↗

CVSS provenance

nvdv3.19.1CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

nvdv2.06.4MEDIUMAV:N/AC:L/Au:N/C:P/I:P/A:N

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