Impact

Specifically crafted malicious themes can execute arbitrary code on the server running Ghost.

Vulnerable Versions

This vulnerability is present in Ghost v0.7.2 to v6.19.0.

Patches

v6.19.1 contains a fix for this issue.

Workarounds

Ghost generally recommends users refrain from installing untrusted themes. If a malicious theme has already been installed, it is recommended to uninstall the theme and then inspect it to understand its impact, which will be attack-specific.

References Ghost thanks Cristian-Alexandru Staicu at Endor Labs for disclosing this vulnerability responsibly.

For more information

If there are any questions or comments about this advisory, email Ghost at security@ghost.org.

DISPUTED An arbitrary file upload vulnerability in the file upload module of Ghost v4.39.0 allows attackers to execute arbitrary code via a crafted SVG file. NOTE: Vendor states that as outlined in Ghost's security documentation, upload of SVGs is only possible by trusted authenticated users. The uploading of SVG files to Ghost does not represent a remote code execution vulnerability. SVGs are not executable on the server, and may only execute javascript in a client's browser - this is expected and intentional functionality.

DISPUTED An arbitrary file upload vulnerability in the file upload module of Ghost CMS v4.42.0 allows attackers to execute arbitrary code via a crafted file. NOTE: Vendor states as detailed in Ghost's security documentation, files can only be uploaded and published by trusted users, this is intentional.

A code execution vulnerability exists in the Statement Bindings functionality of Ghost Foundation node-sqlite3 5.1.1. A specially-crafted Javascript file can lead to arbitrary code execution. An attacker can provide malicious input to trigger this vulnerability.

Impact

When Ghost is behind a shared caching layer that results in cached content being shared between different visitors (e.g., Fastly, Cloudflare, nginx proxycache, and others), an unauthenticated user could send an x-ghost-preview header that altered the rendered frontend response. In affected cache configurations, that response could be stored and served to subsequent visitors requesting the same page, allowing cache poisoning of request-specific preview output.

When running Ghost's frontend and admin panel on the same domain this could be used to take over staff user accounts. When running these on different domains staff accounts have no exposure.

Vulnerable versions

This vulnerability is present in Ghost from v4.0 up to v6.36.0.

Patches

v6.37.0 contains a fix for this issue.

How to update

For self-hosters using Docker, find Docker's official Ghost image here. Updating a Docker-based Ghost instance is documented here.

If your Ghost is a Ghost-CLI install see our documentation on updating it to the latest version here.

If you suspect a credential compromise, use the “Reset all authentication” dialogue under Settings / Danger Zone. This is available starting with Ghost v6.41.0.

Workarounds

At the caching layer, bypass the cache for x-ghost-preview requests.

References

Ghost thanks CryptoCat for disclosing this vulnerability responsibly.

For more information

If you have any questions or comments about this advisory, email us at security@ghost.org.

An authentication bypass vulnerability exists in the newsletter subscription functionality of Ghost Foundation Ghost 5.9.4. A specially-crafted HTTP request can lead to increased privileges. An attacker can send an HTTP request to trigger this vulnerability.

Impact

A SQL injection vulnerability existed in Ghost's Content API that allowed unauthenticated attackers to read arbitrary data from the database.

Vulnerable Versions

This vulnerability is present in Ghost v3.24.0 to v6.19.0.

Patches

v6.19.1 contains a fix for this issue.

Workarounds

There is no application-level workaround. The Content API key is public by design, so restricting key access does not mitigate this vulnerability.

As a temporary mitigation, a reverse proxy or WAF rule can be used to block Content API requests containing slug%3A%5B or slug:[ in the query string filter parameter. Note that this may break legitimate slug filter functionality.

References

We thank Nicholas Carlini using Claude, Anthropic for disclosing this vulnerability responsibly.

For more information If you have any questions or comments about this advisory, email us at security@ghost.org.

Ghost through 5.85.1 allows remote attackers to bypass an authentication rate-limit protection mechanism by using many X-Forwarded-For headers with different values. NOTE: the vendor's position is that Ghost should be installed with a reverse proxy that allows only trusted X-Forwarded-For headers.

Ghost through 5.76.0 allows stored XSS, and resultant privilege escalation in which a contributor can take over any account, via an SVG profile picture that contains JavaScript code to interact with the API on localhost TCP port 3001. NOTE: The discoverer reports that "The vendor does not view this as a valid vector."

An insecure default vulnerability exists in the Post Creation functionality of Ghost Foundation Ghost 5.9.4. Default installations of Ghost allow non-administrator users to inject arbitrary Javascript in posts, which allow privilege escalation to administrator via XSS. To trigger this vulnerability, an attacker can send an HTTP request to inject Javascript in a post to trick an administrator into visiting the post.A stored XSS vulnerability exists in the codeinjectionfoot for a post.

An insecure default vulnerability exists in the Post Creation functionality of Ghost Foundation Ghost 5.9.4. Default installations of Ghost allow non-administrator users to inject arbitrary Javascript in posts, which allow privilege escalation to administrator via XSS. To trigger this vulnerability, an attacker can send an HTTP request to inject Javascript in a post to trick an administrator into visiting the post.A stored XSS vulnerability exists in the codeinjectionhead for a post.

An insecure default vulnerability exists in the Post Creation functionality of Ghost Foundation Ghost 5.9.4. Default installations of Ghost allow non-administrator users to inject arbitrary Javascript in posts, which allow privilege escalation to administrator via XSS. To trigger this vulnerability, an attacker can send an HTTP request to inject Javascript in a post to trick an administrator into visiting the post.A stored XSS vulnerability exists in the facebook field for a user.

An insecure default vulnerability exists in the Post Creation functionality of Ghost Foundation Ghost 5.9.4. Default installations of Ghost allow non-administrator users to inject arbitrary Javascript in posts, which allow privilege escalation to administrator via XSS. To trigger this vulnerability, an attacker can send an HTTP request to inject Javascript in a post to trick an administrator into visiting the post.A stored XSS vulnerability exists in the twitter field for a user.

Ghost before 5.82.0 allows CSV Injection during a member CSV export.

Impact An attacker was able to craft a malicious link that, when accessed by an authenticated staff user or member, would execute JavaScript with the victim's permissions, potentially leading to account takeover.

Vulnerable versions This vulnerability is present in Ghost versions: - v5.43.0 to v5.120.4 - v6.0.0 to v6.14.0

As well as in Portal versions: - v2.29.1 to v2.51.4 - v2.52.0 to v2.57.0

Patches Ghost automatically loads the latest patch of the members Portal component via CDN. Therefore: - For Ghost 5.x users, upgrading to v5.121.0 or later fixes the vulnerability (loads Portal v2.51.5, which contains the patch) - For Ghost 6.x users, upgrading to v6.15.0 or later fixes the vulnerability (loads Portal v2.57.1, which contains the patch)

For Ghost installations using a customised or self-hosted version of Portal, it will be necessary to manually rebuild from or update to the latest patch version.

References Ghost thanks Younes Belalia for discovering and disclosing this vulnerability responsibly.

For more information If users have any questions or comments about this advisory, email Ghost at security@ghost.org.

Impact

Incomplete CSRF protections around /session/verify made it possible to use OTCs in login sessions different from the requesting session. In some scenarios this might have made it easier for phishers to take over a Ghost site.

Vulnerable versions

This vulnerability is present in Ghost from v5.101.6 up to v6.19.2.

Patches

v6.19.3 contains a fix for this issue.

How to update

For self-hosters using Docker, find Docker's official Ghost image here. Updating a Docker-based Ghost instance is documented here.

If a project's Ghost is a Ghost-CLI install see the documentation on updating it to the latest version here.

For more information

If there are any questions or comments about this advisory, send an email to security@ghost.org.

Impact A vulnerability in Ghost's handling of Staff Token authentication allowed certain endpoints to be accessed that were only intended to be accessible via Staff Session authentication. External systems that have been authenticated via Staff Tokens for Admin/Owner-role users would have had access to these endpoints.

Vulnerable versions This vulnerability is present in Ghost v5.121.0 to v5.130.5 to and Ghost v6.0.0 to v6.10.3.

Patches v5.130.6 and v6.11.0 contain a fix for this issue.

References Ghost thanks Sho Odagiri of GMO Cybersecurity by Ierae, Inc. for discovering and disclosing this vulnerability responsibly.

For more information If there are any questions or comments about this advisory, email Ghost at security@ghost.org.

Impact A vulnerability in Ghost's 2FA mechanism allows staff users to skip email 2FA.

Vulnerable versions This vulnerability is present in Ghost v5.105.0 to v5.130.5 to and Ghost v6.0.0 to v6.10.3.

Patches v5.130.6 and v6.11.0 contain a fix for this issue.

References Ghost thanks Sho Odagiri of GMO Cybersecurity by Ierae, Inc. for discovering and disclosing this vulnerability responsibly.

For more information If there are any questions or comments about this advisory, email Ghost at security@ghost.org.

Server-side request forgery (SSRF) vulnerability in Ghost CMS < 3.10.0 allows an attacker to scan local or external network or otherwise interact with internal systems.

Impact

Due to a lack of validation when filtering on the public API endpoints, it is possible to reveal private fields via a brute force attack.

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 below v5.46.1. Immediate action should be taken to secure your site - see patches and workarounds below.

Patches

v5.46.1 contains a fix for this issue.

Workarounds

Add a block for requests to /ghost/api/content/ where the filter query parameter contains password or email.

For more information

If you have any questions or comments about this advisory:

Email us at security@ghost.org

Ghost before 5.42.1 allows remote attackers to read arbitrary files within the active theme's folder via /assets/built%2F..%2F..%2F/ directory traversal. This occurs in frontend/web/middleware/static-theme.js.

The package sqlite3 before 5.0.3 are vulnerable to Denial of Service (DoS) which will invoke the toString function of the passed parameter. If passed an invalid Function object it will throw and crash the V8 engine.

Impact A vulnerability in Ghost's /ghost/api/admin/members/events endpoint allows users with authentication credentials for the Admin API to execute arbitrary SQL.

Vulnerable versions This vulnerability is present in Ghost v5.90.0 to v5.130.5 to and Ghost v6.0.0 to v6.10.3.

Patches v5.130.6 and v6.11.0 contain a fix for this issue.

References Ghost thanks Sho Odagiri of GMO Cybersecurity by Ierae, Inc. for discovering and disclosing this vulnerability responsibly.

For more information If there are any questions or comments about this advisory, email Ghost at security@ghost.org.

Ghost is a Node.js content management system. An error in the implementation of the limits service between versions 4.0.0 and 4.9.4 allows all authenticated users (including contributors) to view admin-level API keys via the integrations API endpoint, leading to a privilege escalation vulnerability. This issue is patched in Ghost version 4.10.0. As a workaround, disable all non-Administrator accounts to prevent API access. It is highly recommended to regenerate all API keys after patching or applying the workaround.

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.

Impact

Improper authentication on some endpoints used for member actions would allow an attacker to perform member-only actions, and read member information.

Vulnerable versions

This security vulnerability is present in Ghost v4.46.0-v5.89.5.

Ghost(Pro) customers are automatically updated to fixed versions ahead of disclosure.

If you're a self-hoster, please follow our update instructions.

Patches

v5.89.5 contains a fix for this issue.

Workarounds

Disable site membership in Ghost settings.

For more information

If you have any questions or comments about this advisory:

Email us at security@ghost.org

Impact

A vulnerability in Ghost's oEmbed mechanism allows staff users to exfiltrate data from internal systems via SSRF.

Vulnerable versions

This vulnerability is present in Ghost v5.99.0 to v5.130.3 to and Ghost v6.0.0 to v6.0.8.

Patches

v5.130.4 and v6.0.9 contain a fix for this issue.

References

The original report is available here: https://fluidattacks.com/advisories/regida

We thank Cristian Vargas for discovering and disclosing this vulnerability responsibly.

For more information

If you have any questions or comments about this advisory, email us at security@ghost.org.

The ghost plugin before 0.5.6 for WordPress has no access control for wp-admin/tools.php?ghostexport=true downloads of exported data.

Impact

A vulnerability in Ghost allows authenticated users to upload files which are symlinks. This can be exploited to perform an arbitrary file read of any file on the operating system.

Site administrators can check for exploitation of this issue by looking for unknown symlinks within Ghost's content/ folder

Vulnerable versions

This security vulnerability is present in Ghost ≤ v5.59.0.

Patches

v5.59.1 contains a fix for this issue.

For more information

If you have any questions or comments about this advisory: Email us at security@ghost.org

Ghost CLI before 1.30.1 contains an IP spoofing vulnerability that allows unauthenticated remote attackers to bypass rate-limiting controls by manipulating the X-Forwarded-For header through a misconfigured Nginx configuration. Attackers can append attacker-controlled values to the header chain using the $proxyaddxforwardedfor directive to present an arbitrary IP address, circumventing Ghost's rate-limiting mechanisms on self-hosted instances.