Vulnerability record · CVE-2021-29484 · published 29 April 2021
CVE-2021-29484: Ghost cross-site scripting vulnerability
Ghost · Ghost
Ghost is a Node.js CMS. An unused endpoint added during the development of 4.0.0 has left sites vulnerable to untrusted users gaining access to Ghost Admin. Attackers can gain access by getting logged in users to click a link containing malicious code. Users do not need to enter credentials and may not know they've visited a malicious site. Ghost(Pro) has already been patched. We can find no evidence that the issue was exploited on Ghost(Pro) prior to the patch being added. Self-hosters are impacted if running Ghost a version between 4.0.0 and 4.3.2. Immediate action should be taken to secure your site. The issue has been fixed in 4.3.3, all 4.x sites should upgrade as soon as possible. As the endpoint is unused, the patch simply removes it. As a workaround blocking access to /ghost/preview can also mitigate the issue.
Description
Ghost is a Node.js CMS. An unused endpoint added during the development of 4.0.0 has left sites vulnerable to untrusted users gaining access to Ghost Admin. Attackers can gain access by getting logged in users to click a link containing malicious code. Users do not need to enter credentials and may not know they've visited a malicious site. Ghost(Pro) has already been patched. We can find no evidence that the issue was exploited on Ghost(Pro) prior to the patch being added. Self-hosters are impacted if running Ghost a version between 4.0.0 and 4.3.2. Immediate action should be taken to secure your site. The issue has been fixed in 4.3.3, all 4.x sites should upgrade as soon as possible. As the endpoint is unused, the patch simply removes it. As a workaround blocking access to /ghost/preview can also mitigate the issue.
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
Affected products
1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.
References
| Link | Tags |
|---|---|
| https://blog.sonarsource.com/ghost-admin-takeover | ExploitThird Party Advisory |
| https://forum.ghost.org/t/critical-security-update-available-for-ghost-4-x/22290 | Vendor Advisory |
| https://github.com/TryGhost/Ghost/security/advisories/GHSA-9fgx-q25h-jxrg | MitigationThird Party Advisory |
| https://www.npmjs.com/package/ghost | ProductThird Party Advisory |
| https://blog.sonarsource.com/ghost-admin-takeover | ExploitThird Party Advisory |
| https://forum.ghost.org/t/critical-security-update-available-for-ghost-4-x/22290 | Vendor Advisory |
| https://github.com/TryGhost/Ghost/security/advisories/GHSA-9fgx-q25h-jxrg | MitigationThird Party Advisory |
| https://www.npmjs.com/package/ghost | ProductThird Party Advisory |
Track CVE-2021-29484 inside VULONE
Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.
Related vulnerabilities
Same products first, then exploited flaws of the same weakness class.
Source: NIST National Vulnerability Database (record CVE-2021-29484), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.
