-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Xen Security Advisory CVE-2013-1920 / XSA-47 Potential use of freed memory in event channel operations ISSUE DESCRIPTION ================= Wrong ordering of operations upon extending the per-domain event channel tracking table can cause a pointer to freed memory to be left in place, when the hypervisor is under memory pressure and XSM (Xen Security Module) is enabled. IMPACT ====== Malicious guest kernels could inject arbitrary events or corrupt other hypervisor state, possibly leading to code execution. VULNERABLE SYSTEMS ================== All Xen versions from 3.2 onwards are vulnerable when making use of XSM. Configurations without XSM or with a dummy module are not affected. MITIGATION ========== Running without XSM (which is the default) will avoid this vulnerability, albeit doing so will likely lower overall security of systems that would otherwise have XSM enabled. RESOLUTION ========== Applying the appropriate attached patch resolves this issue. xsa47-4.1.patch Xen 4.1.x xsa47-4.2-unstable.patch Xen 4.2.x and xen-unstable $ sha256sum xsa47*.patch e49a03e0693de07ec1418eb16191854458e72088febd6948ea5bc1f900a1853a xsa47-4.1.patch c29b59492f9d7e3f74bfc41877a2c5cff70436d3738fd91066f396f969aab0a7 xsa47-4.2-unstable.patch $ -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iQEcBAEBAgAGBQJRXb5fAAoJEIP+FMlX6CvZ0RwH/AtcVQFvERB+16wSjN3GTguk LnakHD3NCVeaDNbkF0G4b4ibR5oOCAGO/9CQwcB1QKj67mvYJm2kglDnGWUmZUQC TKWZR5vA9D9YAQvll8mSwd3OdLBoN0IGYPp9AIVUi9zl34zF+ZzbtsC57dvmjQD6 /E0tMDgOoCsA8ARnuknjbgk+CbfsGi/dbxYGDla4/wMC9wbUhG1wcA9lqNa37azT 1lRIj8qI3TfWC4aMh1kZKPsljrHZLkfA2VxgkrTCjr7u2Usr7vgUsNT4F0rYouRI h5mo1JszJOnM2EHuzVbQrvBmaXlPIFF/S5cRvD6RIavEsOUet5au49Hnhb/ENG4= =/g6f -----END PGP SIGNATURE-----