CVE-2018-8897

Description

A statement in the System Programming Guide of the Intel 64 and IA-32 Architectures Software Developer's Manual (SDM) was mishandled in the development of some or all operating-system kernels, resulting in unexpected behavior for #DB exceptions that are deferred by MOV SS or POP SS, as demonstrated by (for example) privilege escalation in Windows, macOS, some Xen configurations, or FreeBSD, or a Linux kernel crash. The MOV to SS and POP SS instructions inhibit interrupts (including NMIs), data breakpoints, and single step trap exceptions until the instruction boundary following the next instruction (SDM Vol. 3A; section 6.8.3). (The inhibited data breakpoints are those on memory accessed by the MOV to SS or POP to SS instruction itself.) Note that debug exceptions are not inhibited by the interrupt enable (EFLAGS.IF) system flag (SDM Vol. 3A; section 2.3). If the instruction following the MOV to SS or POP to SS instruction is an instruction like SYSCALL, SYSENTER, INT 3, etc. that transfers control to the operating system at CPL < 3, the debug exception is delivered after the transfer to CPL < 3 is complete. OS kernels may not expect this order of events and may therefore experience unexpected behavior when it occurs.

References

https://xenbits.xen.org/xsa/advisory-260.html

https://www.triplefault.io/2018/05/spurious-db-exceptions-with-pop-ss.html

https://www.synology.com/support/security/Synology_SA_18_21

https://www.kb.cert.org/vuls/id/631579

https://www.freebsd.org/security/advisories/FreeBSD-SA-18:06.debugreg.asc

https://www.exploit-db.com/exploits/45024/

https://www.exploit-db.com/exploits/44697/

https://www.debian.org/security/2018/dsa-4201

https://www.debian.org/security/2018/dsa-4196

https://usn.ubuntu.com/3641-2/

https://usn.ubuntu.com/3641-1/

https://svnweb.freebsd.org/base?view=revision&revision=333368

https://support.citrix.com/article/CTX234679

https://support.apple.com/HT208742

https://security.netapp.com/advisory/ntap-20180927-0002/

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8897

https://patchwork.kernel.org/patch/10386677/

https://lists.debian.org/debian-lts-announce/2018/11/msg00013.html

https://lists.debian.org/debian-lts-announce/2018/06/msg00000.html

https://lists.debian.org/debian-lts-announce/2018/05/msg00015.html

https://help.ecostruxureit.com/display/public/UADCE725/Security+fixes+in+StruxureWare+Data+Center+Expert+v7.6.0

https://github.com/torvalds/linux/commit/d8ba61ba58c88d5207c1ba2f7d9a2280e7d03be9

https://github.com/can1357/CVE-2018-8897/

https://bugzilla.redhat.com/show_bug.cgi?id=1567074

https://access.redhat.com/errata/RHSA-2018:1524

https://access.redhat.com/errata/RHSA-2018:1355

https://access.redhat.com/errata/RHSA-2018:1354

https://access.redhat.com/errata/RHSA-2018:1353

https://access.redhat.com/errata/RHSA-2018:1352

https://access.redhat.com/errata/RHSA-2018:1351

https://access.redhat.com/errata/RHSA-2018:1350

https://access.redhat.com/errata/RHSA-2018:1349

https://access.redhat.com/errata/RHSA-2018:1348

https://access.redhat.com/errata/RHSA-2018:1347

https://access.redhat.com/errata/RHSA-2018:1346

https://access.redhat.com/errata/RHSA-2018:1345

https://access.redhat.com/errata/RHSA-2018:1319

https://access.redhat.com/errata/RHSA-2018:1318

http://www.securitytracker.com/id/1040882

http://www.securitytracker.com/id/1040866

http://www.securitytracker.com/id/1040861

http://www.securitytracker.com/id/1040849

http://www.securitytracker.com/id/1040744

http://www.securityfocus.com/bid/104071

http://www.huawei.com/en/psirt/security-advisories/huawei-sa-20190921-01-debug-en

http://openwall.com/lists/oss-security/2018/05/08/4

http://openwall.com/lists/oss-security/2018/05/08/1

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d8ba61ba58c88d5207c1ba2f7d9a2280e7d03be9

Details

Source: Mitre, NVD

Risk Information

CVSS v2

CVSS v3