Cyber Resilience

CVE-2021-26103

Medium

Published: 08 December 2021

Published
08 December 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 6.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L
EPSS Score 0.0029 53.0th percentile
Risk Priority 13 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-26103 is a medium-severity Insufficient Verification of Data Authenticity (CWE-345) vulnerability in Fortinet Fortios. Its CVSS base score is 6.3 (Medium).

Operationally, ranked in the top 47.0% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

An insufficient verification of data authenticity vulnerability (CWE-345) in the user interface of FortiProxy verison 2.0.3 and below, 1.2.11 and below and FortiGate verison 7.0.0, 6.4.6 and below, 6.2.9 and below of SSL VPN portal may allow a remote, unauthenticated…

more

attacker to conduct a cross-site request forgery (CSRF) attack . Only SSL VPN in web mode or full mode are impacted by this vulnerability.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

fortinet
fortiproxy
1.2.0 — 1.2.11 · 2.0.0 — 2.0.3
fortinet
fortios
7.0.0 · 5.6.0 — 5.6.14 · 6.0.0 — 6.0.13 · 6.2.0 — 6.2.9

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-345

Directly requires independent verification of matching output before adverse decisions, mitigating insufficient authenticity checks on data from external sources.

addresses: CWE-345

Use of approved PKI certificates provides verifiable data authenticity and origin for communications and artifacts.

addresses: CWE-345

Mandates provision of authenticity and integrity artifacts that enable verification of name/address resolution data.

addresses: CWE-345

Requires explicit verification of data authenticity from authoritative sources, preventing acceptance of unauthenticated resolution responses.

addresses: CWE-345

Control requires verification of data authenticity/integrity (e.g., checksums) after aggregation/packing, directly reducing exploitation of insufficient verification before transmission.

addresses: CWE-345

Time synchronization supports reliable freshness verification when checking data authenticity across systems or components.

addresses: CWE-345

Mandates verification of data authenticity for software, firmware, and information.

addresses: CWE-345

Provenance documentation and monitoring directly enables verification of authenticity for components and data throughout their history.

References