CVE-2021-21087ColdFusion XSS
Adobe Coldfusion versions 2016 (update 16 and earlier), 2018 (update 10 and earlier) and 2021.0.0.323925 are affected by an Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability.
Published Mar 23, 2021 · Updated Apr 23, 2025
Key Facts
Patch immediately- CVE-2021-21087 is a medium-severity vulnerability (CVSS 5.4 v3.1) affecting ColdFusion (Adobe).
- It is exploited in the wild, listed in CIRCL KEV, Industry KEV feed since Oct 18, 2023. No public exploit code is known.
- EPSS estimates a 37% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
Scores
CVSS v3.1
5.4
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
EPSS (30-day exploit likelihood)
37%
Higher than 98.5% of all scored CVEs
Exploit maturity
Exploited (KEV)
ATLAS score
51/100
Publication score, see How it works
Exploitation Verdict
KEV listed
Oct 18, 2023
939 days after publication
Federal due date
None
No federal due date
Ransomware use
Not reported
Attributed actors
None named
Exploit & Defence Guidance
Exploit maturity
Exploited (KEV)
Public exploit code
0
Proof-of-concept links
In-the-wild evidence
10
Reports of active use
Advisories And Exploit References
- advisoryhttps://www.bleepingcomputer.com/news/security/critical-code-execution-vulnerability-fixed-in-adobe-coldfusion/Critical
- advisoryhttps://www.cybersecurity-help.cz/vdb/SB2021032222
- advisoryhttps://www.cybersecurity-help.cz/vdb/SB2021032222Remote
- advisoryhttps://www.itsecuritynews.info/adobe-patches-critical-coldfusion-security-flaw/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed:+ItSecurityNewsAggregated+(IT+Security+News)Adobe
- advisoryUSOM advisory
- patchhttps://helpx.adobe.com/security/products/coldfusion/apsb21-16.html
Description
Adobe Coldfusion versions 2016 (update 16 and earlier), 2018 (update 10 and earlier) and 2021.0.0.323925 are affected by an Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability. An attacker could abuse this vulnerability to execute arbitrary JavaScript code in context of the current user. Exploitation of this issue requires user interaction.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CIRCL KEV | Oct 18, 2023 | n/a | Not reported |
| Industry KEV feed | Oct 18, 2023 | n/a | Not reported |
Affected Products
30 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| ColdFusionAdobe | 2016, 2016-update1, 2016-update10, 2016-update11, 2016-update12, 2016-update13, 2016-update14, 2016-update15 | n/a |
Timeline
Publicly disclosed
Mar 23, 2021
Added to CIRCL KEV
Oct 18, 2023
Added to Industry KEV feed
Oct 18, 2023
Last updated
Apr 23, 2025
Weakness Type
- CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
References
- advisorybleepingcomputer.com · Critical
- advisorycybersecurity-help.cz · SB2021032222
- advisorycybersecurity-help.cz · SB2021032222Remote
- advisoryitsecuritynews.info · adobe-patches-critical-coldfusion-security-flaw
- advisoryUSOM advisory
FAQ
Common Questions.
Adobe Coldfusion versions 2016 (update 16 and earlier), 2018 (update 10 and earlier) and 2021.0.0.323925 are affected by an Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability.
Affected: ColdFusion (Adobe) versions 2016, 2016-update1, 2016-update10, 2016-update11, 2016-update12, 2016-update13, 2016-update14, 2016-update15. The full list is in the CVE brief.
It is exploited in the wild, listed in CIRCL KEV, Industry KEV feed since Oct 18, 2023.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
Is CVE-2021-21087 On Your Attack Surface?
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