CVE-2018-8897
What it is
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.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 18.5% chance of exploitation in the next 30 days (EPSS). Higher than most.
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 18.5% in the next 30 days (EPSS).
- Severity: 7.8 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 18.5% · EPSS, next 30 days
- Weakness
- CWE-362 · Race condition
- Record status
- Modified
Affected
- Debian Linux 7.0
- Debian Linux 8.0
- Debian Linux 9.0
- Canonical Ubuntu Linux 14.04
- Canonical Ubuntu Linux 16.04
- Canonical Ubuntu Linux 17.10
- Redhat Enterprise Linux Server 7.0
- Redhat Enterprise Linux Workstation 7.0
Attack profile CVSS 3.0 · 7.8
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2018-8897.md and follow it. Check whether this project is affected by CVE-2018-8897. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d8ba61ba58c88d5207c1ba2f7d9a2280e7d03be9
- https://github.com/torvalds/linux/commit/d8ba61ba58c88d5207c1ba2f7d9a2280e7d03be9
- https://patchwork.kernel.org/patch/10386677/
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8897
- https://xenbits.xen.org/xsa/advisory-260.html
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d8ba61ba58c88d5207c1ba2f7d9a2280e7d03be9
- https://github.com/torvalds/linux/commit/d8ba61ba58c88d5207c1ba2f7d9a2280e7d03be9
- https://patchwork.kernel.org/patch/10386677/
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8897
- https://xenbits.xen.org/xsa/advisory-260.html
References
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d8ba61ba58c88d5207c1ba2f7d9a2280e7d03be9
- http://openwall.com/lists/oss-security/2018/05/08/1
- http://openwall.com/lists/oss-security/2018/05/08/4
- http://www.huawei.com/en/psirt/security-advisories/huawei-sa-20190921-01-debug-en
- http://www.securityfocus.com/bid/104071
- http://www.securitytracker.com/id/1040744
- http://www.securitytracker.com/id/1040849
- http://www.securitytracker.com/id/1040861
- http://www.securitytracker.com/id/1040866
- http://www.securitytracker.com/id/1040882
- https://access.redhat.com/errata/RHSA-2018:1318
- https://access.redhat.com/errata/RHSA-2018:1319
- https://access.redhat.com/errata/RHSA-2018:1345
- https://access.redhat.com/errata/RHSA-2018:1346
- https://access.redhat.com/errata/RHSA-2018:1347
- https://access.redhat.com/errata/RHSA-2018:1348
- https://access.redhat.com/errata/RHSA-2018:1349
- https://access.redhat.com/errata/RHSA-2018:1350
- https://access.redhat.com/errata/RHSA-2018:1351
- https://access.redhat.com/errata/RHSA-2018:1352
- https://access.redhat.com/errata/RHSA-2018:1353
- https://access.redhat.com/errata/RHSA-2018:1354
- https://access.redhat.com/errata/RHSA-2018:1355
- https://access.redhat.com/errata/RHSA-2018:1524
- https://bugzilla.redhat.com/show_bug.cgi?id=1567074