An issue was discovered in Xen through 4.14.x.
An issue was discovered in Xen through 4.14.x. x86 PV guest kernels can experience denial of service via SYSENTER. The SYSENTER instruction leaves various state sanitization activities to software. One of Xen's sanitization paths injects a #GP fault, and incorrectly delivers it twice to the guest. This causes the guest kernel to observe a kernel-privilege #GP fault (typically fatal) rather than a user-privilege #GP fault (usually converted into SIGSEGV/etc.). Malicious or buggy userspace can crash the guest kernel, resulting in a VM Denial of Service. All versions of Xen from 3.2 onwards are vulnerable. Only x86 systems are vulnerable. ARM platforms are not vulnerable. Only x86 systems that support the SYSENTER instruction in 64bit mode are vulnerable. This is believed to be Intel, Centaur, and Shanghai CPUs. AMD and Hygon CPUs are not believed to be vulnerable. Only x86 PV guests can exploit the vulnerability. x86 PVH / HVM guests cannot exploit the vulnerability.
- Published
- Sep 23, 2020
- Updated
- Jun 16, 2026
- EPSS
- 0.5% · 42th percentile
- CWE
- CWE-74
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Report tools
Action score
22
Monitor
Low priority for now.
- CVSS
- 22 / 40 · 5.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.5%
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| xen | xen | cpe:2.3:o:xen:xen |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
| opensuse | leap | cpe:2.3:o:opensuse:leap |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- debian debian linux10.0
- fedoraproject fedora31
- fedoraproject fedora32
- fedoraproject fedora33
- opensuse leap15.2
- xen xen3.2.0 and later · up to 4.14.0 inclusive
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Alpine:v3.10 | xen | from 3.2.0 · before 4.12.3-r4 | 4.12.3-r4 |
| Alpine:v3.11 | xen | from 3.2.0 · before 4.13.1-r4 | 4.13.1-r4 |
| Alpine:v3.13 | xen | from 3.2.0 · before 4.14.0-r1 | 4.14.0-r1 |
| Alpine:v3.9 | xen | from 3.2.0 · before 4.11.4-r2 | 4.11.4-r2 |
| Debian:10 | xen | before 4.11.4+37-g3263f257ca-1 | 4.11.4+37-g3263f257ca-1 |
| Debian:12 | xen | before 4.14.0+80-gd101b417b7-1 | 4.14.0+80-gd101b417b7-1 |
| openSUSE:Leap 15.2 | xen | before 4.13.1_08-lp152.2.9.1 | 4.13.1_08-lp152.2.9.1 |
| SUSE:HPE Helion OpenStack 8 | xen | before 4.9.4_12-3.74.1 | 4.9.4_12-3.74.1 |
| SUSE:Linux Enterprise High Performance Computing 15-ESPOS | xen | before 4.10.4_16-3.41.1 | 4.10.4_16-3.41.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP1 | xen | before 4.12.3_08-3.28.1 | 4.12.3_08-3.28.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP2 | xen | before 4.13.1_08-3.10.1 | 4.13.1_08-3.10.1 |
| SUSE:Linux Enterprise Server 11 SP4-LTSS | xen | before 4.4.4_44-61.55.1 | 4.4.4_44-61.55.1 |
| SUSE:Linux Enterprise Software Development Kit 12 SP5 | xen | before 4.12.3_08-3.24.1 | 4.12.3_08-3.24.1 |
| SUSE:OpenStack Cloud 7 | xen | before 4.7.6_10-43.67.1 | 4.7.6_10-43.67.1 |
| SUSE:OpenStack Cloud 9 | xen | before 4.11.4_08-2.36.1 | 4.11.4_08-2.36.1 |
Same product
xen: all recordsOther highest-scoring records for the same primary product.
- CVE-2017-10921The grant-table feature in Xen through 4.8.x does not ensure sufficient type counts for a GNTMAP_device_map and GNTMAP_host_map mapping, whi41Plan
- CVE-2017-10920The grant-table feature in Xen through 4.8.x mishandles a GNTMAP_device_map and GNTMAP_host_map mapping, when followed by only a GNTMAP_host41Plan
- CVE-2017-10918Xen through 4.8.x does not validate memory allocations during certain P2M operations, which allows guest OS users to obtain privileged host 41Plan
- CVE-2017-10912Xen through 4.8.x mishandles page transfer, which allows guest OS users to obtain privileged host OS access, aka XSA-217.41Plan
- CVE-2015-8104The KVM subsystem in the Linux kernel through 4.2.6, and Xen 4.3.x through 4.6.x, allows guest OS users to cause a denial of service (host O41Plan
- CVE-2015-5165The C+ mode offload emulation in the RTL8139 network card device model in QEMU, as used in Xen 4.5.x and earlier, allows remote attackers to41Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| alpine:xen | 4.12.3-r4 · Alpine:v3.10 | Package registry (OSV) |
| debian:xen | 4.14.0+80-gd101b417b7-1 · Debian:12 | Package registry (OSV) |
| opensuse:xen | 4.13.1_08-lp152.2.9.1 · openSUSE:Leap 15.2 | Package registry (OSV) |
| suse:xen | 4.4.4_44-61.55.1 · SUSE:Linux Enterprise Server 11 SP4-LTSS | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-20-781 · Sep 24, 2020(Xen Zafiyeti)
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-74 · Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Server Side Include (SSI) InjectionCAPEC-101likelihood: High · High
- HTTP Request SplittingCAPEC-105likelihood: Medium · High
- Command Line Execution through SQL InjectionCAPEC-108likelihood: Low · Very High
- Double EncodingCAPEC-120likelihood: Low · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
- Format String InjectionCAPEC-135likelihood: High · High
- Client-side Injection-induced Buffer OverflowCAPEC-14likelihood: Medium · High
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- lists.opensuse.org/opensuse-security-announce/2020-10/msg00008.html
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4JRXMKEMQRQYWYEPHVBIWUEAVQ3LU4FN/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DA633Y3G5KX7MKRN4PFEGM3IVTJMBEOM/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RJZERRBJN6E6STDCHT4JHP4MI6TKBCJE/
- security.gentoo.org/glsa/202011-06
- www.debian.org/security/2020/dsa-4769
- xenbits.xen.org/xsa/advisory-339.html
Vendor advisories and official records. Exploit/PoC links are deliberately left out.