Security readout for executives and security teams
Plain-English summary
CKEditor 4 could execute JavaScript from malformed Fake Objects HTML when vulnerable plugins are used. In business terms, this is a stored or content-driven cross-site scripting risk in sites that let users or staff create rich HTML content with affected CKEditor versions.
Executive priority
Treat this as a high-priority patching issue where CKEditor handles trusted business content, customer portals, or admin workflows. The main risk is unauthorized script execution against users who view crafted content, potentially exposing sessions or sensitive application data.
Technical view
CVE-2021-37695 is CWE-79 in CKEditor 4 Fake Objects package before 4.16.2. The CVSS 3.1 vector requires network access, low complexity, low privileges, and user interaction, with high confidentiality and integrity impact and no availability impact.
Likely exposure
Exposure is most likely in web applications, CMS workflows, admin portals, or bundled products using CKEditor 4 with affected Fake Objects plugin versions below 4.16.2. Downstream Fedora, Debian LTS, and Oracle advisories indicate packaged or embedded exposure should be checked.
Exploitation context
The supplied sources do not show CISA KEV listing or active exploitation. Exploitation requires an attacker with some content-editing ability and a victim interaction path where malformed Fake Objects HTML is rendered or processed by the vulnerable editor.
Researcher notes
Do not assume all CKEditor 4 deployments are affected; the vulnerable path is tied to Fake Objects package usage before 4.16.2. The bundle names a patch but provides no supported evidence of public exploitation. Validate exposure through version and plugin inventory, not generic CKEditor presence alone.
Mitigation direction
- Upgrade CKEditor 4 and Fake Objects usage to version 4.16.2 or later.
- Apply relevant downstream vendor updates for packaged CKEditor dependencies.
- Inventory bundled CKEditor copies inside third-party products and vendor applications.
- Restrict rich-content editing privileges until affected instances are patched.
- Review vendor guidance where CKEditor is embedded by another product.
Validation and detection
- Identify all CKEditor 4 installations and record their exact versions.
- Check whether the Fake Objects package or dependent plugins are enabled.
- Confirm patched deployments report CKEditor 4.16.2 or later.
- Review dependency lockfiles, static assets, and vendor bundles for older copies.
- Check downstream OS or product advisories for applicable package fixes.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-37695 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N2.15.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.3HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/ckeditor/ckeditor4/security/advisories/GHSA-m94c-37g6-cjhcCVE reference · x_refsource_CONFIRM
- https://github.com/ckeditor/ckeditor4/commit/de3c001540715f9c3801aaa38a1917de46cfcf58CVE reference · x_refsource_MISC
- FEDORA-2021-51457da891CVE reference · vendor-advisory, x_refsource_FEDORA
- FEDORA-2021-72176a63a8CVE reference · vendor-advisory, x_refsource_FEDORA
- FEDORA-2021-87578dca12CVE reference · vendor-advisory, x_refsource_FEDORA
- https://www.oracle.com/security-alerts/cpuoct2021.htmlCVE reference · x_refsource_MISC
- [debian-lts-announce] 20211109 [SECURITY] [DLA 2813-1] ckeditor security updateCVE reference · mailing-list, x_refsource_MLIST
- https://www.oracle.com/security-alerts/cpujan2022.htmlCVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.