The virDomainGetHostname API is fetching guest information and this may involve use of an untrusted guest agent. As such its use must be forbidden on a read-only connection to libvirt. Fixes CVE-2019-3886 Signed-off-by: Daniel P. Berrangé <berrange(a)redhat.com&gt; --- src/libvirt-domain.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c index be5b1f6740..baf21824fe 100644 --- a/src/libvirt-domain.c +++ b/src/libvirt-domain.c @@ -11031,6 +11031,8 @@ virDomainGetHostname(virDomainPtr domain, unsigned int flags) virCheckDomainReturn(domain, NULL); conn = domain->conn; + virCheckReadOnlyGoto(domain->conn->flags, error); + if (conn->driver->domainGetHostname) { char *ret; ret = conn->driver->domainGetHostname(domain, flags);

Getting the guest time and hostname both require use of guest agent commands. These must not be allowed for read-only users, so the permissions check must validate "write" permission not "read". Fixes CVE-2019-3886 Signed-off-by: Daniel P. Berrangé <berrange(a)redhat.com&gt; --- src/remote/remote_protocol.x | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/remote/remote_protocol.x b/src/remote/remote_protocol.x index 74be4b37d0..11f44ee267 100644 --- a/src/remote/remote_protocol.x +++ b/src/remote/remote_protocol.x @@ -5513,7 +5513,7 @@ enum remote_procedure { /** * @generate: both - * @acl: domain:read + * @acl: domain:write */ REMOTE_PROC_DOMAIN_GET_HOSTNAME = 277, @@ -5908,7 +5908,7 @@ enum remote_procedure { /** * @generate: none - * @acl: domain:read + * @acl: domain:write */ REMOTE_PROC_DOMAIN_GET_TIME = 337,