Hermes WebUI vulnerabilities

Hermes WebUI before 0.51.443 contains an authorization bypass vulnerability in the session export endpoint that allows authenticated users to access sessions from other profiles. The _handle_session_export handler in api/routes.py fails to verify active-profile ownership before serializing session data.

Hermes WebUI before 0.51.443 contains a broken access control vulnerability in the /api/session endpoint that allows authenticated users to disclose cross-profile session transcripts. Attackers can bypass profile boundary checks by directly querying session IDs belonging to other profiles.

Hermes WebUI before version 0.51.788 contains an unauthenticated remote code execution vulnerability that allows remote attackers to execute arbitrary shell commands by accessing the embedded terminal API endpoints without credentials. Attackers can create a session, attach a PTY shell, and write arbitrary commands through the terminal input endpoint to achieve full command execution as the server process user via four sequential unauthenticated HTTP requests.

Hermes WebUI before version 0.51.307 contains an authentication bypass vulnerability that allows unauthenticated remote attackers to circumvent local-origin IP restrictions on onboarding endpoints by supplying a spoofed X-Forwarded-For header with a loopback address. Attackers can exploit this bypass to perform server-side request forgery against internal services including cloud metadata endpoints, overwrite LLM provider configuration and API keys with attacker-controlled values, or initiate OAuth device-code flows to obtain persistent access tokens stored in auth.json.

Hermes WebUI before 0.51.409 contains an authentication bypass vulnerability in passkey registration endpoints that allows unauthenticated remote attackers to register arbitrary passkeys. When HERMES_WEBUI_PASSKEY=1 is enabled with no existing credentials, POST /api/auth/passkey/register/options and POST /api/auth/passkey/register endpoints are accessible without authentication.

Hermes WebUI before version 0.51.358 contains an improper access control vulnerability that allows unauthenticated remote attackers to hijack initial setup by submitting the _set_password parameter to the settings API endpoint without any network origin restriction. Attackers on any reachable network can send a POST request to the settings endpoint during the first-run setup window to persist an arbitrary password hash, obtain a valid session cookie, and lock out the legitimate operator from their own instance.

A vulnerability in Hermes WebUI before version 0.51.521 allows bypassing profile isolation. When importing a session via the /api/session/import handler, the session object is created without setting its profile, resulting in a null profile. Since a null profile is treated as the default profile, a user on the default profile can export the session transcript and use its session identifier to read files from the named profile's workspace.

Hermes WebUI before 0.51.468 contains a resource exhaustion vulnerability in the unauthenticated POST /api/onboarding/oauth/start endpoint that allows unbounded accumulation of in-memory flow state and daemon threads.

Hermes WebUI before 0.51.368 contains an authorization bypass vulnerability in the get_profile_cookie() function that accepts unauthenticated profile names from the hermes_profile cookie. An authenticated attacker can forge the hermes_profile cookie value to bypass profile-scoped authorization checks and access sessions, files, and resources across different profiles.

Hermes WebUI before version 0.51.311 contains a remote code execution vulnerability that allows authenticated attackers to execute arbitrary commands by placing malicious executable Git configuration in a workspace repository's .git/config file. Attackers can exploit Git subprocess invocations in api/workspace_git.py through vectors such as core.fsmonitor, protocol.ext.allow, credential.helper, core.askPass, core.gitProxy, or inherited environment variables including GIT_SSH_COMMAND.

Hermes WebUI before version 0.51.303 contains a TOCTOU race condition vulnerability in the git_discard function within api/workspace_git.py, allowing attackers to delete files outside the configured workspace boundary by replacing a validated path component with a symlink.

Hermes WebUI before version 0.51.296 has a workspace boundary bypass vulnerability. An authenticated attacker can set a remote terminal working directory to a system path like /etc, causing early return before blocked-root checks, allowing read access to system files.

Hermes WebUI before version 0.51.269 contains a profile isolation bypass vulnerability that allows authenticated users to access data belonging to other profiles by querying the session search endpoint without active-profile filtering. Attackers can send requests to the sessions search handler to retrieve session titles and transcript message content from profiles other than their own active profile.

Hermes WebUI before version 0.51.270 contains a resource exhaustion vulnerability that allows unauthenticated remote attackers to degrade service availability by repeatedly calling the passkey options endpoint without completing assertion. Attackers can send unlimited POST requests to the authentication endpoint, causing unbounded growth of the challenge store file and excessive CPU and disk I/O through repeated JSON file rewrites.

Hermes WebUI prior to v0.51.221 contains a path traversal vulnerability that allows attackers to escape the workspace boundary by supplying symlinks that resolve to files or directories outside the designated workspace root. Attackers can exploit the workspace file and listing APIs, which resolve symlink targets without enforcing that the final path remains within the workspace, to read external host files such as SSH keys, cloud credentials, or application tokens.

Hermes WebUI prior to version 0.51.44 contains a path traversal vulnerability in the session import endpoint. Authenticated attackers can read arbitrary files by importing a crafted session with an unrestricted workspace value.