|author||Jason A. Donenfeld <Jason@zx2c4.com>||2020-11-21 14:59:03 +0100|
|committer||Jason A. Donenfeld <Jason@zx2c4.com>||2020-11-22 22:00:32 +0100|
|parent||manager: move IPC notification to go routine per client (diff)|
conf: allow administrators to add and remove configs easily
We loosen the permissions a little bit while tightening the restrictions on encrypted files. This should allow administrators to easily drop unencrypted files into Data\Configurations\ and get them encrypted and made read-only, while also allowing them to delete unwanted configurations. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Diffstat (limited to 'attacksurface.md')
1 files changed, 2 insertions, 1 deletions
diff --git a/attacksurface.md b/attacksurface.md
index 553806cf..eb8baade 100644
@@ -29,7 +29,8 @@ The manager service is a userspace service running as Local System, responsible
- Extensive IPC using unnamed pipes, inherited by the UI process.
- A readable `CreateFileMapping` handle to a binary ringlog shared by all services, inherited by the UI process.
- It listens for service changes in tunnel services according to the string prefix "WireGuardTunnel$".
- - It manages DPAPI-encrypted configuration files in `C:\Program Files\WireGuard\Data`, which is created with `O:SYG:SYD:PAI(A;OICI;FA;;;SY)(A;OICI;FR;;;BA)`, and makes some effort to enforce good configuration filenames.
+ - It manages DPAPI-encrypted configuration files in `C:\Program Files\WireGuard\Data`, which is created with `O:SYG:SYD:PAI(A;OICI;FA;;;SY)(A;OICI;FA;;;BA)`, and makes some effort to enforce good configuration filenames.
+ - The actual DPAPI-encrypted configuration files are created with `O:SYG:SYD:PAI(A;;FA;;;SY)(A;;SD;;;BA)`.
- It uses `WTSEnumerateSessions` and `WTSSESSION_NOTIFICATION` to walk through each available session. It then uses `WTSQueryUserToken`, and then calls `GetTokenInformation(TokenGroups)` on it. If one of the returned group's SIDs matches `IsWellKnownSid(WinBuiltinAdministratorsSid)`, and has attributes of either `SE_GROUP_ENABLED` or `SE_GROUP_USE_FOR_DENY_ONLY` and calling `GetTokenInformation(TokenElevation)` on it or its `TokenLinkedToken` indicates that either is elevated, then it spawns the UI process as that the elevated user token, passing it three unnamed pipe handles for IPC and the log mapping handle, as described above.
- In the event that the administrator has set `HKLM\Software\WireGuard\LimitedOperatorUI` to 1, sessions are started for users that are a member of group S-1-5-32-556, with a more limited IPC interface, in which these non-admin users are denied private keys and tunnel editing rights. (This means users can potentially DoS the IPC server by draining notifications too slowly, or exhausting memory of the manager by spawning too many watcher go routines, or by sending garbage data that Go's `gob` decoder isn't expecting.)