CVE-2018-8897

Advisory lineage Upstream: 0 Downstream: 92
Modified
Published: 08 May 2018, 18:00
Last modified:05 Aug 2024, 07:10

Vulnerability Summary

Overall Risk (default)
medium
46/100
CVSS Score
7.8 HIGH
v3.0 (nvd)
EPSS Score
24.72% HIGH
25% probability -0.07%
KEV
Not listed
Ransomware
No reports
Public exploits
4 found
Dark Web
Not detected

Timeline

08 May 2018, 18:00
Published
Vulnerability first disclosed
05 Aug 2024, 07:10
Last Modified
Vulnerability information updated

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.

CVSS Metrics

  • v3.0•HIGH•Score: 7.8CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
  • v2.0•HIGH•Score: 7.2AV:L/AC:L/Au:N/C:C/I:C/A:C

EPSS Trends

Current EPSS score: 24.72%• Percentile: 96%

Techniques & Countermeasures

  • CWE-362•Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

    The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

Affected Systems

  • apple•mac_os_x

    < 10.13.4

  • canonical•ubuntu_linux

    14.04 | 16.04 | 17.10

  • citrix•xenserver

    6.0.2 | 6.2.0 | 6.5 | 7.0 | 7.1 | 7.2 | 7.3 | 7.4

  • debian•debian_linux

    7.0 | 8.0 | 9.0

  • freebsd•freebsd

    ≥ 11.0, < 11.1

  • redhat•enterprise_linux_server

    7.0

  • redhat•enterprise_linux_workstation

    7.0

  • redhat•enterprise_virtualization_manager

    3.0

  • synology•diskstation_manager

    5.2 | 6.0 | 6.1

  • synology•skynas

    na

  • xen•xen

    na

References (48)