Vulnerability findings for the public-facing infrastructure of claude.ai
01 Executive overview Severity distribution across 101 findings
02 Top findings Ranked by severity
Highest-impact issues identified during the assessment (non-informational), ordered by severity.
| # | Severity | Finding | Affected | Instances |
|---|---|---|---|---|
| 01 | High | PII Disclosure | claude.ai | 2 |
| 02 | Medium | CSP: Wildcard Directive | claude.ai | 5 |
| 03 | Medium | CSP: style-src unsafe-inline | claude.ai | 5 |
| 04 | Medium | Source Code Disclosure - SQL | claude.ai | 2 |
| 05 | Medium | Sub Resource Integrity Attribute Missing | claude.ai | 5 |
| 06 | Low | Cookie No HttpOnly Flag | claude.ai | 5 |
| 07 | Low | Cookie with SameSite Attribute None | claude.ai | 5 |
| 08 | Low | Cookie without SameSite Attribute | claude.ai | 3 |
| 09 | Low | Cross-Domain JavaScript Source File Inclusion | claude.ai | 5 |
| 10 | Low | Cross-Origin-Embedder-Policy Header Missing or Invalid | claude.ai | 5 |
| 11 | Low | Cross-Origin-Opener-Policy Header Missing or Invalid | claude.ai | 5 |
| 12 | Low | Private IP Disclosure | claude.ai | 12 |
| 13 | Low | Server Leaks Information via "X-Powered-By" HTTP Response Header Field(s) | claude.ai | 5 |
| 14 | Low | Strict-Transport-Security Header Not Set | claude.ai | 5 |
| 15 | Low | Timestamp Disclosure - Unix | claude.ai | 5 |
| 16 | Low | X-Content-Type-Options Header Missing | claude.ai | 5 |
| 17 | Informational | Content Security Policy (CSP) Report-Only Header Found | claude.ai | 5 |
| 18 | Informational | Modern Web Application | claude.ai | 5 |
| 19 | Informational | Non-Storable Content | claude.ai | 4 |
| 20 | Informational | Re-examine Cache-control Directives | claude.ai | 5 |
| 21 | Informational | Session Management Response Identified | claude.ai | 12 |
| 22 | Informational | Storable but Non-Cacheable Content | claude.ai | 1 |
03 Findings Detailed observations, ordered by severity
Each finding records what was observed, where it was observed, and supporting evidence from the scanning toolchain.
PII Disclosure
The response contains Personally Identifiable Information, such as CC number, SSN and similar sensitive data.
Check the response for the potential presence of personally identifiable information (PII), ensure nothing sensitive is leaked by the application.
CSP: Wildcard Directive
Content Security Policy (CSP) is an added layer of security that helps to detect and mitigate certain types of attacks. Including (but not limited to) Cross Site Scripting (XSS), and data injection attacks. These attacks are used for everything from data theft to site defacement or distribution of malware. CSP provides a set of standard HTTP headers that allow website owners to declare approved sources of content that browsers should be allowed to load on that page — covered types are JavaScript, CSS, HTML frames, fonts, images and embeddable objects such as Java applets, ActiveX, audio and video files.
Ensure that your web server, application server, load balancer, etc. is properly configured to set the Content-Security-Policy header.
- https://www.w3.org/TR/CSP/
- https://caniuse.com/#search=content+security+policy
- https://content-security-policy.com/
- https://github.com/HtmlUnit/htmlunit-csp
- https://web.dev/articles/csp#resource-options
CSP: style-src unsafe-inline
Content Security Policy (CSP) is an added layer of security that helps to detect and mitigate certain types of attacks. Including (but not limited to) Cross Site Scripting (XSS), and data injection attacks. These attacks are used for everything from data theft to site defacement or distribution of malware. CSP provides a set of standard HTTP headers that allow website owners to declare approved sources of content that browsers should be allowed to load on that page — covered types are JavaScript, CSS, HTML frames, fonts, images and embeddable objects such as Java applets, ActiveX, audio and video files.
Ensure that your web server, application server, load balancer, etc. is properly configured to set the Content-Security-Policy header.
- https://www.w3.org/TR/CSP/
- https://caniuse.com/#search=content+security+policy
- https://content-security-policy.com/
- https://github.com/HtmlUnit/htmlunit-csp
- https://web.dev/articles/csp#resource-options
Source Code Disclosure - SQL
Application Source Code was disclosed by the web server. - SQL
Ensure that application Source Code is not available with alternative extensions, and ensure that source code is not present within other files or data deployed to the web server, or served by the web server.
- https://nhimg.org/twitter-breach
Sub Resource Integrity Attribute Missing
The integrity attribute is missing on a script or link tag served by an external server. The integrity tag prevents an attacker who have gained access to this server from injecting a malicious content.
Provide a valid integrity attribute to the tag.
- https://developer.mozilla.org/en-US/docs/Web/Security/Subresource_Integrity
Cookie No HttpOnly Flag
A cookie has been set without the HttpOnly flag, which means that the cookie can be accessed by JavaScript. If a malicious script can be run on this page then the cookie will be accessible and can be transmitted to another site. If this is a session cookie then session hijacking may be possible.
Ensure that the HttpOnly flag is set for all cookies.
- https://owasp.org/www-community/HttpOnly
Cookie with SameSite Attribute None
A cookie has been set with its SameSite attribute set to "none", which means that the cookie can be sent as a result of a 'cross-site' request. The SameSite attribute is an effective counter measure to cross-site request forgery, cross-site script inclusion, and timing attacks.
Ensure that the SameSite attribute is set to either 'lax' or ideally 'strict' for all cookies.
- https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-cookie-same-site
Cookie without SameSite Attribute
A cookie has been set without the SameSite attribute, which means that the cookie can be sent as a result of a 'cross-site' request. The SameSite attribute is an effective counter measure to cross-site request forgery, cross-site script inclusion, and timing attacks.
Ensure that the SameSite attribute is set to either 'lax' or ideally 'strict' for all cookies.
- https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-cookie-same-site
Cross-Domain JavaScript Source File Inclusion
The page includes one or more script files from a third-party domain.
Ensure JavaScript source files are loaded from only trusted sources, and the sources can't be controlled by end users of the application.
Cross-Origin-Embedder-Policy Header Missing or Invalid
Cross-Origin-Embedder-Policy header is a response header that prevents a document from loading any cross-origin resources that don't explicitly grant the document permission (using CORP or CORS).
Ensure that the application/web server sets the Cross-Origin-Embedder-Policy header appropriately, and that it sets the Cross-Origin-Embedder-Policy header to 'require-corp' for documents.
If possible, ensure that the end user uses a standards-compliant and modern web browser that supports the Cross-Origin-Embedder-Policy header (https://caniuse.com/mdn-http_headers_cross-origin-embedder-policy).
- https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/Cross-Origin-Embedder-Policy
Cross-Origin-Opener-Policy Header Missing or Invalid
Cross-Origin-Opener-Policy header is a response header that allows a site to control if others included documents share the same browsing context. Sharing the same browsing context with untrusted documents might lead to data leak.
Ensure that the application/web server sets the Cross-Origin-Opener-Policy header appropriately, and that it sets the Cross-Origin-Opener-Policy header to 'same-origin' for documents.
'same-origin-allow-popups' is considered as less secured and should be avoided.
If possible, ensure that the end user uses a standards-compliant and modern web browser that supports the Cross-Origin-Opener-Policy header (https://caniuse.com/mdn-http_headers_cross-origin-opener-policy).
- https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/Cross-Origin-Opener-Policy
Private IP Disclosure
A private IP (such as 10.x.x.x, 172.x.x.x, 192.168.x.x) or an Amazon EC2 private hostname (for example, ip-10-0-56-78) has been found in the HTTP response body. This information might be helpful for further attacks targeting internal systems.
Remove the private IP address from the HTTP response body. For comments, use JSP/ASP/PHP comment instead of HTML/JavaScript comment which can be seen by client browsers.
- https://datatracker.ietf.org/doc/html/rfc1918
Server Leaks Information via "X-Powered-By" HTTP Response Header Field(s)
The web/application server is leaking information via one or more "X-Powered-By" HTTP response headers. Access to such information may facilitate attackers identifying other frameworks/components your web application is reliant upon and the vulnerabilities such components may be subject to.
Ensure that your web server, application server, load balancer, etc. is configured to suppress "X-Powered-By" headers.
- https://owasp.org/www-project-web-security-testing-guide/v42/4-Web_Application_Security_Testing/01-Information_Gathering/08-Fingerprint_Web_Application_Framework
- https://www.troyhunt.com/shhh-dont-let-your-response-headers/
Strict-Transport-Security Header Not Set
HTTP Strict Transport Security (HSTS) is a web security policy mechanism whereby a web server declares that complying user agents (such as a web browser) are to interact with it using only secure HTTPS connections (i.e. HTTP layered over TLS/SSL). HSTS is an IETF standards track protocol and is specified in RFC 6797.
Ensure that your web server, application server, load balancer, etc. is configured to enforce Strict-Transport-Security.
- https://cheatsheetseries.owasp.org/cheatsheets/HTTP_Strict_Transport_Security_Cheat_Sheet.html
- https://owasp.org/www-community/Security_Headers
- https://en.wikipedia.org/wiki/HTTP_Strict_Transport_Security
- https://caniuse.com/stricttransportsecurity
- https://datatracker.ietf.org/doc/html/rfc6797
Timestamp Disclosure - Unix
A timestamp was disclosed by the application/web server. - Unix
Manually confirm that the timestamp data is not sensitive, and that the data cannot be aggregated to disclose exploitable patterns.
- https://cwe.mitre.org/data/definitions/200.html
X-Content-Type-Options Header Missing
The Anti-MIME-Sniffing header X-Content-Type-Options was not set to 'nosniff'. This allows older versions of Internet Explorer and Chrome to perform MIME-sniffing on the response body, potentially causing the response body to be interpreted and displayed as a content type other than the declared content type. Current (early 2014) and legacy versions of Firefox will use the declared content type (if one is set), rather than performing MIME-sniffing.
Ensure that the application/web server sets the Content-Type header appropriately, and that it sets the X-Content-Type-Options header to 'nosniff' for all web pages.
If possible, ensure that the end user uses a standards-compliant and modern web browser that does not perform MIME-sniffing at all, or that can be directed by the web application/web server to not perform MIME-sniffing.
- https://learn.microsoft.com/en-us/previous-versions/windows/internet-explorer/ie-developer/compatibility/gg622941(v=vs.85)
- https://owasp.org/www-community/Security_Headers
Content Security Policy (CSP) Report-Only Header Found
The response contained a Content-Security-Policy-Report-Only header, this may indicate a work-in-progress implementation, or an oversight in promoting pre-Prod to Prod, etc.
Content Security Policy (CSP) is an added layer of security that helps to detect and mitigate certain types of attacks, including Cross Site Scripting (XSS) and data injection attacks. These attacks are used for everything from data theft to site defacement or distribution of malware. CSP provides a set of standard HTTP headers that allow website owners to declare approved sources of content that browsers should be allowed to load on that page — covered types are JavaScript, CSS, HTML frames, fonts, images and embeddable objects such as Java applets, ActiveX, audio and video files.
Ensure that your web server, application server, load balancer, etc. is configured to set the Content-Security-Policy header.
- https://www.w3.org/TR/CSP2/
- https://w3c.github.io/webappsec-csp/
- https://caniuse.com/#feat=contentsecuritypolicy
- https://content-security-policy.com/
Modern Web Application
The application appears to be a modern web application. If you need to explore it automatically then the Ajax Spider may well be more effective than the standard one.
This is an informational alert and so no changes are required.
Non-Storable Content
The response contents are not storable by caching components such as proxy servers. If the response does not contain sensitive, personal or user-specific information, it may benefit from being stored and cached, to improve performance.
The content may be marked as storable by ensuring that the following conditions are satisfied:
The request method must be understood by the cache and defined as being cacheable ("GET", "HEAD", and "POST" are currently defined as cacheable)
The response status code must be understood by the cache (one of the 1XX, 2XX, 3XX, 4XX, or 5XX response classes are generally understood)
The "no-store" cache directive must not appear in the request or response header fields
For caching by "shared" caches such as "proxy" caches, the "private" response directive must not appear in the response
For caching by "shared" caches such as "proxy" caches, the "Authorization" header field must not appear in the request, unless the response explicitly allows it (using one of the "must-revalidate", "public", or "s-maxage" Cache-Control response directives)
In addition to the conditions above, at least one of the following conditions must also be satisfied by the response:
It must contain an "Expires" header field
It must contain a "max-age" response directive
For "shared" caches such as "proxy" caches, it must contain a "s-maxage" response directive
It must contain a "Cache Control Extension" that allows it to be cached
It must have a status code that is defined as cacheable by default (200, 203, 204, 206, 300, 301, 404, 405, 410, 414, 501).
- https://datatracker.ietf.org/doc/html/rfc7234
- https://datatracker.ietf.org/doc/html/rfc7231
- https://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html
Re-examine Cache-control Directives
The cache-control header has not been set properly or is missing, allowing the browser and proxies to cache content. For static assets like css, js, or image files this might be intended, however, the resources should be reviewed to ensure that no sensitive content will be cached.
For secure content, ensure the cache-control HTTP header is set with "no-cache, no-store, must-revalidate". If an asset should be cached consider setting the directives "public, max-age, immutable".
- https://cheatsheetseries.owasp.org/cheatsheets/Session_Management_Cheat_Sheet.html#web-content-caching
- https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/Cache-Control
- https://grayduck.mn/2021/09/13/cache-control-recommendations/
Session Management Response Identified
The given response has been identified as containing a session management token. The 'Other Info' field contains a set of header tokens that can be used in the Header Based Session Management Method. If the request is in a context which has a Session Management Method set to "Auto-Detect" then this rule will change the session management to use the tokens identified.
This is an informational alert rather than a vulnerability and so there is nothing to fix.
- https://www.zaproxy.org/docs/desktop/addons/authentication-helper/session-mgmt-id/
Storable but Non-Cacheable Content
The response contents are storable by caching components such as proxy servers, but will not be retrieved directly from the cache, without validating the request upstream, in response to similar requests from other users.
- https://datatracker.ietf.org/doc/html/rfc7234
- https://datatracker.ietf.org/doc/html/rfc7231
- https://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html
04 Network & transport 79 observations
| # | Endpoint | Service | Detail | Severity |
|---|---|---|---|---|
| N-01 | 160.79.104.10:443 | https | Service https on 160.79.104.10:443/tcp | Info |
| N-02 | 160.79.104.10:80 | http | Service http on 160.79.104.10:80/tcp | Info |
| N-03 | 160.79.104.10:8080 | http-proxy | Service http-proxy on 160.79.104.10:8080/tcp | Info |
| N-04 | 160.79.104.10:8443 | https-alt | Service https-alt on 160.79.104.10:8443/tcp | Info |
| N-05 | https://claude.ai/ | Status 302 | https://claude.ai/login Cloudflare, Cloudflare Bot Management, HTTP/3 | Info |
| N-06 | a.claude.ai | subfinder | source: hackertarget | Info |
| N-07 | cloud.a.claude.ai | subfinder | source: submd | Info |
| N-08 | demo.assets.claude.ai | subfinder | source: submd | Info |
| N-09 | internal.a.claude.ai | subfinder | source: submd | Info |
| N-10 | stats.claude.ai | subfinder | source: submd | Info |
| N-11 | storage.claude.ai | subfinder | source: submd | Info |
| N-12 | aws.a-cdn.claude.ai | subfinder | source: submd | Info |
| N-13 | external.a.claude.ai | subfinder | source: submd | Info |
| N-14 | monitor.downloads.claude.ai | subfinder | source: submd | Info |
| N-15 | my.claude.ai | subfinder | source: submd | Info |
| N-16 | account.claude.ai | subfinder | source: submd | Info |
| N-17 | dns2.claude.ai | subfinder | source: submd | Info |
| N-18 | staging.a-cdn.claude.ai | subfinder | source: submd | Info |
| N-19 | assets.a.claude.ai | subfinder | source: submd | Info |
| N-20 | my.a.claude.ai | subfinder | source: submd | Info |
| N-21 | autodiscover.downloads.claude.ai | subfinder | source: submd | Info |
| N-22 | files.a.claude.ai | subfinder | source: submd | Info |
| N-23 | sql.downloads.claude.ai | subfinder | source: submd | Info |
| N-24 | webmail.downloads.claude.ai | subfinder | source: submd | Info |
| N-25 | alpha.a.claude.ai | subfinder | source: submd | Info |
| N-26 | dns1.a.claude.ai | subfinder | source: submd | Info |
| N-27 | go.assets.claude.ai | subfinder | source: submd | Info |
| N-28 | jenkins.downloads.claude.ai | subfinder | source: submd | Info |
| N-29 | stats.a.claude.ai | subfinder | source: submd | Info |
| N-30 | ads.a.claude.ai | subfinder | source: submd | Info |
| N-31 | images.a.claude.ai | subfinder | source: submd | Info |
| N-32 | live.a.claude.ai | subfinder | source: submd | Info |
| N-33 | store.assets.claude.ai | subfinder | source: submd | Info |
| N-34 | v1.a.claude.ai | subfinder | source: submd | Info |
| N-35 | azure.assets.claude.ai | subfinder | source: submd | Info |
| N-36 | cdn.a-cdn.claude.ai | subfinder | source: submd | Info |
| N-37 | mx.assets.claude.ai | subfinder | source: submd | Info |
| N-38 | sandbox.a-cdn.claude.ai | subfinder | source: submd | Info |
| N-39 | files.claude.ai | subfinder | source: submd | Info |
| N-40 | kubernetes.a.claude.ai | subfinder | source: submd | Info |
| N-41 | status.downloads.claude.ai | subfinder | source: submd | Info |
| N-42 | v2.a.claude.ai | subfinder | source: submd | Info |
| N-43 | pop.downloads.claude.ai | subfinder | source: submd | Info |
| N-44 | static.assets.claude.ai | subfinder | source: submd | Info |
| N-45 | aws.a.claude.ai | subfinder | source: submd | Info |
| N-46 | git.a.claude.ai | subfinder | source: submd | Info |
| N-47 | mail1.a.claude.ai | subfinder | source: submd | Info |
| N-48 | shop.claude.ai | subfinder | source: submd | Info |
| N-49 | test.assets.claude.ai | subfinder | source: submd | Info |
| N-50 | news.a.claude.ai | subfinder | source: submd | Info |
| N-51 | private.a.claude.ai | subfinder | source: submd | Info |
| N-52 | test.a-cdn.claude.ai | subfinder | source: submd | Info |
| N-53 | upload.downloads.claude.ai | subfinder | source: submd | Info |
| N-54 | demo.a-cdn.claude.ai | subfinder | source: submd | Info |
| N-55 | admin.downloads.claude.ai | subfinder | source: submd | Info |
| N-56 | host.claude.ai | subfinder | source: submd | Info |
| N-57 | mail2.claude.ai | subfinder | source: submd | Info |
| N-58 | media.a.claude.ai | subfinder | source: submd | Info |
| N-59 | owa.downloads.claude.ai | subfinder | source: submd | Info |
| N-60 | secure.assets.claude.ai | subfinder | source: submd | Info |
| N-61 | smtp.downloads.claude.ai | subfinder | source: submd | Info |
| N-62 | ns4.claude.ai | subfinder | source: submd | Info |
| N-63 | track.downloads.claude.ai | subfinder | source: submd | Info |
| N-64 | webmail.a.claude.ai | subfinder | source: submd | Info |
| N-65 | app.a-cdn.claude.ai | subfinder | source: submd | Info |
| N-66 | ns2.claude.ai | subfinder | source: submd | Info |
| N-67 | staging.claude.ai | subfinder | source: thc | Info |
| N-68 | www.claude.ai | subfinder | source: thc | Info |
| N-69 | console.claude.ai | subfinder | source: thc | Info |
| N-70 | a.preview.claude.ai | subfinder | source: thc | Info |
| N-71 | api.claude.ai | subfinder | source: thc | Info |
| N-72 | livepreview.claude.ai | subfinder | source: thc | Info |
| N-73 | status.claude.ai | subfinder | source: thc | Info |
| N-74 | downloads.preview.claude.ai | subfinder | source: thc | Info |
| N-75 | pivot.claude.ai | subfinder | source: thc | Info |
| N-76 | downloads.claude.ai | subfinder | source: thc | Info |
| N-77 | a-cdn.claude.ai | subfinder | source: thc | Info |
| N-78 | preview.claude.ai | subfinder | source: thc | Info |
| N-79 | assets.claude.ai | subfinder | source: thc | Info |
05 Additional informational findings 0 items
| # | Finding | Affected | Instances |
|---|