CVE-2021-22122Network attack vector

Reflected XSS via unneutralized API input

Published Feb 8, 2021 · Updated Oct 25, 2024

Reflected XSS in the Fortinet FortiWeb GUI before 6.2.4 and 6.3.0 through 6.3.7 allows remote attackers to execute script via API input. The GUI returns attacker-controlled API input in generated pages without neutralizing executable markup; Fortinet does not identify the endpoints. A victim must open the crafted request, after which the script runs in that victim's browser context and can act with the victim's GUI access.

CVSS severity6.1
Medium
EPSS probability10.52%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in the Fortinet FortiWeb GUI before 6.2.4 and 6.3.0 through 6.3.7 allows remote attackers to execute script via API input. The GUI returns attacker-controlled API input in generated pages without neutralizing executable markup; Fortinet does not identify the endpoints. A victim must open the crafted request, after which the script runs in that victim's browser context and can act with the victim's GUI access.

The record

CVE
CVE-2021-22122
Published
Feb 8, 2021
Updated
Oct 25, 2024
Vendor
Fortinet
Product
FortiWeb
Classifications
CWE-79, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 8, 2021CVE publishedPublication date reported by the CVE source.
  2. Oct 25, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=FortiWeb 6.3.0 through 6.3.7 and version before 6.2.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Fortinet · FortiWebversion=FortiWeb 6.3.0 through 6.3.7 and version before 6.2.4

Published CVSS scores

6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1189Drive-by Compromise

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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