CVE-2014-7823: dumpxml: security hole with migratable flag

Commit 28f8dfd (v1.0.0) introduced a security hole: in at least
the qemu implementation of virDomainGetXMLDesc, the use of the
flag VIR_DOMAIN_XML_MIGRATABLE (which is usable from a read-only
connection) triggers the implicit use of VIR_DOMAIN_XML_SECURE
prior to calling qemuDomainFormatXML.  However, the use of
VIR_DOMAIN_XML_SECURE is supposed to be restricted to read-write
clients only.  This patch treats the migratable flag as requiring
the same permissions, rather than analyzing what might break if
migratable xml no longer includes secret information.

Fortunately, the information leak is low-risk: all that is gated
by the VIR_DOMAIN_XML_SECURE flag is the VNC connection password;
but VNC passwords are already weak (FIPS forbids their use, and
on a non-FIPS machine, anyone stupid enough to trust a max-8-byte
password sent in plaintext over the network deserves what they
get).  SPICE offers better security than VNC, and all other
secrets are properly protected by use of virSecret associations
rather than direct output in domain XML.

* src/remote/remote_protocol.x (REMOTE_PROC_DOMAIN_GET_XML_DESC):
Tighten rules on use of migratable flag.
* src/libvirt-domain.c (virDomainGetXMLDesc): Likewise.

Signed-off-by: Eric Blake <eblake@redhat.com>

diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c
index 7dc31469e9e57719fccbccf1569a3f4d8f871a53..2b0defc75d43e9aacb82823db80b41b4cfc367d0 100644 (file)
--- a/src/libvirt-domain.c
+++ b/src/libvirt-domain.c
@@ -2607,7 +2607,8 @@ virDomainGetXMLDesc(virDomainPtr domain, unsigned int flags)
     virCheckDomainReturn(domain, NULL);
     conn = domain->conn;
 
-    if ((conn->flags & VIR_CONNECT_RO) && (flags & VIR_DOMAIN_XML_SECURE)) {
+    if ((conn->flags & VIR_CONNECT_RO) &&
+        (flags & (VIR_DOMAIN_XML_SECURE | VIR_DOMAIN_XML_MIGRATABLE))) {
         virReportError(VIR_ERR_OPERATION_DENIED, "%s",
                        _("virDomainGetXMLDesc with secure flag"));
         goto error;

diff --git a/src/remote/remote_protocol.x b/src/remote/remote_protocol.x
index db12cdadd0a9f2771e0a4933928e2c333ff6be2b..ebf453071a6959fa7e5cfc3fcb00e1308af0a759 100644 (file)
--- a/src/remote/remote_protocol.x
+++ b/src/remote/remote_protocol.x
@@ -3255,6 +3255,7 @@ enum remote_procedure {
      * @generate: both
      * @acl: domain:read
      * @acl: domain:read_secure:VIR_DOMAIN_XML_SECURE
+     * @acl: domain:read_secure:VIR_DOMAIN_XML_MIGRATABLE
      */
     REMOTE_PROC_DOMAIN_GET_XML_DESC = 14,