The image proxy got an ssrfSafeTransport in commit aca0cff3 that resolves
DNS first, blocks any IP in private/reserved CIDRs, then dials by IP to
defeat DNS rebinding. The TitleExtractor used to construct comments'
PostTitle from Locator.URL — a user-supplied field — was missed by that
fix and kept using http.DefaultTransport. The hostname allowlist there
checks the parsed URL host but never the IP it resolves to, so a domain
suffix-matching an allowed host (or 127.0.0.1 itself when AllowedHosts
is empty) reaches the metadata service or any other internal endpoint.
The same gosec rule (G704) was excluded globally in .golangci.yml as part
of aca0cff3, so this gap was not caught by the linter either.
Extract the transport into a new safehttp package so it lives in one
place and can be reused, then pass safehttp.Transport() into the
TitleExtractor's http.Client at construction (cmd/server.go). The image
proxy switches to safehttp.Transport() too — same behaviour, no longer
duplicated.
Reproduction in title_test.go uses the production-style client to hit
an httptest.Server (always 127.0.0.1) and asserts the dialer refuses
even though "127.0.0.1" is in the allowed-domains list. A control case
shows the same setup without safehttp.Transport returns the page —
making the original vulnerability explicit.
Apply go fix ./... analysers (Go 1.26) across backend and examples:
- interface{} → any (type alias, no behaviour change)
- for i := 0; i < N; i++ → for range N / for i := range N
- slices.Contains / slices.ContainsFunc replacing manual loops
- strings.SplitSeq replacing strings.Split in range (avoids allocation)
- strings.CutPrefix replacing HasPrefix+TrimPrefix
- min() replacing manual if/else
- fmt.Appendf replacing []byte(fmt.Sprintf(...))
- strings.Builder replacing string += concatenation
- wg.Go(func(){}) replacing wg.Add(1)/go/wg.Done() pattern
- removed redundant ii := i loop variable copies (unnecessary since Go 1.22)
omitempty on struct-typed JSON fields: go fix removed omitempty from
struct-typed fields (time.Time, PostInfo, UserDetailEntry) because
encoding/json's omitempty never applied to struct types — it was always
a no-op. Kept as bare tags (no omitzero replacement) to preserve the
existing serialisation behaviour.
Replace strings.Split(RemoteAddr, ":") with net.SplitHostPort for correct
IPv6 address extraction in vote deduplication and comment IP tracking.
Harden image proxy: add SSRF-safe transport blocking private/reserved IPs
at connection time with DNS rebinding protection, sanitize error messages
to prevent information leakage, add response size limit via io.LimitReader.
Fix shadowed error variables in BlockedUsers, SetTitle, and Delete methods.
Exclude gosec taint analysis false positives at linter config level.
Add AUTH_MICROSOFT_TENANT env var to allow configuring the Azure AD
tenant for single-tenant Entra ID applications, which cannot use the
default /common endpoint.
Depends on go-pkgz/auth#266
Closes#1998
With AUTH_SEND_JWT_HEADER=true, frontend now properly handles JWT authentication:
- Store JWT token in client-side cookie named 'JWT'
- Extract and store XSRF token from JWT payload
- Set Secure flag automatically when on HTTPS connection
- Update documentation to clarify this behavior
This fixes an issue where login state would be lost after page reload
when using header-based JWT authentication.
This clarifies that the parameter sets CSP 'frame-ancestors'
to limit hosts allowed to embed comments. The commit also improves
the documentation on how to use ALLOWED_HOSTS with AUTH_SAME_SITE
for different setup scenarios.
We might want to change AUTH_SAME_SITE to `strong` in v2.0 as it works
on the subdomain of the same site as well as current Lax option.
`Content-Security-Policy` now restricts resource loading and execution
to enhance security:
- `default-src 'none'`: Disallow all resource loading by default.
- `base-uri 'none'`: Prevents the use of `<base>` tag to change the
base URL for relative URLs.
- `form-action 'none'`: Disallows form submissions.
- `connect-src 'self'`: Restricts the origins that can be connected to
(via XHR, WebSockets, etc.) to the same origin.
- `frame-src 'self'`: Restricts the origins that can be embedded using
`<frame>` and `<iframe>` to the same origin (for `/web/` demo
endpoint).
- `frame-ancestors %s;`: Specifies the origins that are allowed to
embed this content in a frame. If no specific origins are allowed, it
defaults to `*` (any origin). This enhances security by controlling
which sites can embed your content.
- `img-src 'self'`: Allows images to be loaded only from the same
origin. If `imageProxyEnabled` is true, allows images from any origin
(`*`).
- `script-src 'self' 'unsafe-inline'`: Allows scripts to be loaded and
executed only from the same origin and allows inline scripts.
- `style-src 'self' 'unsafe-inline'`: Allows styles to be loaded and
applied only from the same origin and allows inline styles.
- `font-src data:`: Allows fonts to be loaded from data URIs.
- `object-src 'none'`: Disallows the use of `<object>`, `<embed>`, and
`<applet>` tags.
`Permissions-Policy` now restricts the use of certain browser features
which we don't use to enhance user privacy and security:
- `accelerometer=()`: Disables the use of the accelerometer sensor.
- `autoplay=()`: Disables automatic playback of media.
- `camera=()`: Disables the use of the camera.
- `cross-origin-isolated=()`: Disallows the page from being treated as
cross-origin isolated.
- `display-capture=()`: Disables the ability to capture the display.
- `encrypted-media=()`: Disables the use of Encrypted Media Extensions
.
- `fullscreen=()`: Disables the ability to use fullscreen mode.
- `geolocation=()`: Disables the use of geolocation.
- `gyroscope=()`: Disables the use of the gyroscope sensor.
- `keyboard-map=()`: Disables the use of the keyboard map.
- `magnetometer=()`: Disables the use of the magnetometer sensor.
- `microphone=()`: Disables the use of the microphone.
- `midi=()`: Disables the use of the MIDI API.
- `payment=()`: Disables the Payment Request API.
- `picture-in-picture=()`: Disables the use of Picture-in-Picture mode
.
- `publickey-credentials-get=()`: Disables the use of the Web
Authentication API.
- `screen-wake-lock=()`: Disables the ability to prevent the screen
from dimming.
- `sync-xhr=()`: Disables synchronous XMLHttpRequest.
- `usb=()`: Disables the use of the USB API.
- `xr-spatial-tracking=()`: Disables the use of spatial tracking in
WebXR.
- `clipboard-read=()`: Disables the ability to read from the clipboard
.
- `clipboard-write=()`: Disables the ability to write to the clipboard
.
- `gamepad=()`: Disables the use of the Gamepad API.
- `hid=()`: Disables the use of the Human Interface Device API.
- `idle-detection=()`: Disables the ability to detect idle state.
- `interest-cohort=()`: Disables the use of interest cohort tracking.
- `serial=()`: Disables the use of the Serial API.
- `unload=()`: Disables the ability to use the `beforeunload` and
`unload` events.
- `window-management=()`: Disables the ability to use window
management APIs.
Allowed domains consist of `REMARK_URL` second-level domain (or whole IP in case it's IP like `127.0.0.1`) and `ALLOWED_HOSTS`. That is needed to prevent Remark42 from asking arbitrary servers and storing the page title as the comment.PostTitle.
Previous behaviour allowed the caller of the API to create a comment
with an arbitrary URL and learn the title of the page, which might be
accessible to the server Remark42 is installed on but not to the user
outside that network (CWE-918).
Allowed domains consist of `REMARK_URL` second-level domain (or whole IP in case it's IP like `127.0.0.1`) and `ALLOWED_HOSTS`. That is needed to prevent Remark42 from asking arbitrary servers and storing the page title as the comment.PostTitle.
Previous behaviour allowed the caller of the API to create a comment
with an arbitrary URL and learn the title of the page, which might be
accessible to the server Remark42 is installed on but not to the user
outside that network (CWE-918).
Without this option, the aud is ignored.
It works only with RPC admin storage.
The shared key returned for all requests with the default shared admin
storage, so enabling that option does not affect it.
After this commit, dev auth would start working with the `REMARK_URL`
hostname instead of the previously hardcoded 127.0.0.1.
Breaks development setup where `REMARK_URL` was set
to a non-standard value and dev auth was running on 127.0.0.1
and working, as, after that change, it would stop working.
