The admin protocol RPC messages are only intended for use by the user running the daemon. As such they should not be allowed for any client UID that does not match the server UID. Fixes CVE-2019-10132 Reviewed-by: Ján Tomko <jtomko(a)redhat.com&gt; Signed-off-by: Daniel P. Berrangé <berrange(a)redhat.com&gt; --- src/admin/admin_server_dispatch.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/src/admin/admin_server_dispatch.c b/src/admin/admin_server_dispatch.c index 85e693d76c..6e3b99f97d 100644 --- a/src/admin/admin_server_dispatch.c +++ b/src/admin/admin_server_dispatch.c @@ -64,6 +64,28 @@ remoteAdmClientNew(virNetServerClientPtr client ATTRIBUTE_UNUSED, void *opaque) { struct daemonAdmClientPrivate *priv; + uid_t clientuid; + gid_t clientgid; + pid_t clientpid; + unsigned long long timestamp; + + if (virNetServerClientGetUNIXIdentity(client, + &clientuid, + &clientgid, + &clientpid, + &timestamp) < 0) + return NULL; + + VIR_DEBUG("New client pid %lld uid %lld", + (long long)clientpid, + (long long)clientuid); + + if (geteuid() != clientuid) { + virReportRestrictedError(_("Disallowing client %lld with uid %lld"), + (long long)clientpid, + (long long)clientuid); + return NULL; + } if (VIR_ALLOC(priv) < 0) return NULL; -- 2.21.0

The virtlogd daemon's only intended client is the libvirtd daemon. As such it should never allow clients from other user accounts to connect. The code already enforces this and drops clients from other UIDs, but we can get earlier (and thus stronger) protection against DoS by setting the socket permissions to 0600 Fixes CVE-2019-10132 Reviewed-by: Ján Tomko <jtomko(a)redhat.com&gt; Signed-off-by: Daniel P. Berrangé <berrange(a)redhat.com&gt; --- src/logging/virtlogd-admin.socket.in | 1 + src/logging/virtlogd.socket.in | 1 + 2 files changed, 2 insertions(+) diff --git a/src/logging/virtlogd-admin.socket.in b/src/logging/virtlogd-admin.socket.in index 595e6c4c4b..5c41dfeb7b 100644 --- a/src/logging/virtlogd-admin.socket.in +++ b/src/logging/virtlogd-admin.socket.in @@ -5,6 +5,7 @@ Before=libvirtd.service [Socket] ListenStream=@localstatedir@/run/libvirt/virtlogd-admin-sock Service=virtlogd.service +SocketMode=0600 [Install] WantedBy=sockets.target diff --git a/src/logging/virtlogd.socket.in b/src/logging/virtlogd.socket.in index 22b9360c8d..ae48cdab9a 100644 --- a/src/logging/virtlogd.socket.in +++ b/src/logging/virtlogd.socket.in @@ -4,6 +4,7 @@ Before=libvirtd.service [Socket] ListenStream=@localstatedir@/run/libvirt/virtlogd-sock +SocketMode=0600 [Install] WantedBy=sockets.target -- 2.21.0