CVE-2021-20487
https://notcve.org/view.php?id=CVE-2021-20487
IBM Power9 Self Boot Engine(SBE) could allow a privileged user to inject malicious code and compromise the integrity of the host firmware bypassing the host firmware signature verification process. IBM Power9 Self Boot Engine (SBE), podría permitir a un usuario privilegiado inyectar código malicioso y comprometer la integridad del firmware del host al omitir el proceso de comprobación de la firma del firmware del host • https://exchange.xforce.ibmcloud.com/vulnerabilities/197730 https://www.ibm.com/support/pages/node/6455911 • CWE-347: Improper Verification of Cryptographic Signature •
CVE-2020-4788 – kernel: speculation on incompletely validated data on IBM Power9
https://notcve.org/view.php?id=CVE-2020-4788
IBM Power9 (AIX 7.1, 7.2, and VIOS 3.1) processors could allow a local user to obtain sensitive information from the data in the L1 cache under extenuating circumstances. IBM X-Force ID: 189296. Los procesadores IBM Power9 (AIX versiones 7.1, 7.2 y VIOS versión 3.1), podrían permitir a un usuario local obtener información confidencial de los datos en la caché L1 en circunstancias atenuantes. IBM X-Force ID: 189296 A flaw was found in the Linux kernel. IBM Power9 processors can speculatively operate on data stored in the L1 cache before it has been completely validated. • http://www.openwall.com/lists/oss-security/2020/11/20/3 http://www.openwall.com/lists/oss-security/2020/11/23/1 https://exchange.xforce.ibmcloud.com/vulnerabilities/189296 https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TITJQPYDWZ4NB2ONJWUXW75KSQIPF35T https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZF4OGZPKTAJJXWHPIFP3LHEWWEMR5LPT https://www.ibm.com/support/pages/node/6370729 https://www.oracle.com/security-alerts/cpujul • CWE-200: Exposure of Sensitive Information to an Unauthorized Actor •
CVE-2017-1000255 – kernel: Arbitrary stack overwrite causing oops via crafted signal frame
https://notcve.org/view.php?id=CVE-2017-1000255
On Linux running on PowerPC hardware (Power8 or later) a user process can craft a signal frame and then do a sigreturn so that the kernel will take an exception (interrupt), and use the r1 value *from the signal frame* as the kernel stack pointer. As part of the exception entry the content of the signal frame is written to the kernel stack, allowing an attacker to overwrite arbitrary locations with arbitrary values. The exception handling does produce an oops, and a panic if panic_on_oops=1, but only after kernel memory has been over written. This flaw was introduced in commit: "5d176f751ee3 (powerpc: tm: Enable transactional memory (TM) lazily for userspace)" which was merged upstream into v4.9-rc1. Please note that kernels built with CONFIG_PPC_TRANSACTIONAL_MEM=n are not vulnerable. • http://www.securityfocus.com/bid/101264 https://access.redhat.com/errata/RHSA-2018:0654 https://access.redhat.com/security/cve/CVE-2017-1000255 https://bugzilla.redhat.com/show_bug.cgi?id=1498067 • CWE-787: Out-of-bounds Write •