[pbs-devel] [PATCH proxmox-backup] access: limit editing pam credentials to superuser

[Oguz Bektas]

modifying @pam users' credentials should be only allowed for root at pam,
otherwise it can have unintended consequences.

Signed-off-by: Oguz Bektas <o.bektas at proxmox.com>
---
 src/api2/access/user.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/api2/access/user.rs b/src/api2/access/user.rs
index 484919bf..7c19db2f 100644
--- a/src/api2/access/user.rs
+++ b/src/api2/access/user.rs
@@ -350,8 +350,11 @@ pub fn update_user(
     email: Option<String>,
     delete: Option<Vec<DeletableProperty>>,
     digest: Option<String>,
+    rpcenv: &mut dyn RpcEnvironment,
 ) -> Result<(), Error> {
 
+    let user_info = CachedUserInfo::new()?;
+
     let _lock = open_file_locked(user::USER_CFG_LOCKFILE, std::time::Duration::new(10, 0), true)?;
 
     let (mut config, expected_digest) = user::config()?;
@@ -391,8 +394,13 @@ pub fn update_user(
         data.expire = if expire > 0 { Some(expire) } else { None };
     }
 
+
     if let Some(password) = password {
+        let source_auth_id = rpcenv.get_auth_id().unwrap().parse()?;
         let authenticator = crate::auth::lookup_authenticator(userid.realm())?;
+        if userid.realm() == "pam" && !user_info.is_superuser(&source_auth_id) {
+            bail!("only superuser can edit this!");
+        }
         authenticator.store_password(userid.name(), &password)?;
     }
 
-- 
2.20.1