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.
This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 7.8, requiring local system access to exploit with relatively low complexity without requiring user interaction requiring only low-level privileges . The vulnerability impacts confidentiality (data exposure), integrity (unauthorized modifications), and availability (service disruption) for affected systems. Impacting 11 products from debian, from canonical, from redhat and 8 others, organizations running these solutions should prioritize assessment and patching.
First disclosed in 2018, this vulnerability was reported during a period defined by widespread IoT adoption challenges, mobile security concerns, and the emergence of advanced persistent threat (APT) techniques. Contemporary mitigation strategies focused on secure development practices and third-party component vetting.
2018-05-08T18:29:00.547
2024-11-21T04:14:33.140
Modified
CVSSv3.0: 7.8 (HIGH)
AV:L/AC:L/Au:N/C:C/I:C/A:C
3.9
10.0
| Type | Vendor | Product | Version/Range | Vulnerable? |
|---|---|---|---|---|
| Operating System | debian | debian_linux | 7.0 | Yes |
| Operating System | debian | debian_linux | 8.0 | Yes |
| Operating System | debian | debian_linux | 9.0 | Yes |
| Operating System | canonical | ubuntu_linux | 14.04 | Yes |
| Operating System | canonical | ubuntu_linux | 16.04 | Yes |
| Operating System | canonical | ubuntu_linux | 17.10 | Yes |
| Operating System | redhat | enterprise_linux_server | 7.0 | Yes |
| Operating System | redhat | enterprise_linux_workstation | 7.0 | Yes |
| Operating System | redhat | enterprise_virtualization_manager | 3.0 | Yes |
| Application | citrix | xenserver | 6.0.2 | Yes |
| Application | citrix | xenserver | 6.2.0 | Yes |
| Application | citrix | xenserver | 6.5 | Yes |
| Application | citrix | xenserver | 7.0 | Yes |
| Application | citrix | xenserver | 7.1 | Yes |
| Application | citrix | xenserver | 7.2 | Yes |
| Application | citrix | xenserver | 7.3 | Yes |
| Application | citrix | xenserver | 7.4 | Yes |
| Application | synology | skynas | - | Yes |
| Operating System | synology | diskstation_manager | 5.2 | Yes |
| Operating System | synology | diskstation_manager | 6.0 | Yes |
| Operating System | synology | diskstation_manager | 6.1 | Yes |
| Operating System | apple | mac_os_x | < 10.13.4 | Yes |
| Operating System | xen | xen | - | Yes |
| Operating System | freebsd | freebsd | < 11.1 | Yes |
SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For debian's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.