HOMEVULNERABILITIESCVE-2019-18425
CRITICAL

CVE-2019-18425

CWE-269Published: October 31, 2019· Updated: Jun 17, 2026

9.8
CVSS v3.1

Official Description

An issue was discovered in Xen through 4.12.x allowing 32-bit PV guest OS users to gain guest OS privileges by installing and using descriptors. There is missing descriptor table limit checking in x86 PV emulation. When emulating certain PV guest operations, descriptor table accesses are performed by the emulating code. Such accesses should respect the guest specified limits, unless otherwise guaranteed to fail in such a case. Without this, emulation of 32-bit guest user mode calls through call gates would allow guest user mode to install and then use descriptors of their choice, as long as the guest kernel did not itself install an LDT. (Most OSes don't install any LDT by default). 32-bit PV guest user mode can elevate its privileges to that of the guest kernel. Xen versions from at least 3.2 onwards are affected. Only 32-bit PV guest user mode can leverage this vulnerability. HVM, PVH, as well as 64-bit PV guests cannot leverage this vulnerability. Arm systems are unaffected.

NVD Source

Technical Analysis

CVE-2019-18425 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

Debian1 product(s)
debian linux
Fedora1 product(s)
fedora
openSUSE1 product(s)
leap
xen1 product(s)
xen
Source: NVD CPE · 7 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttp://xenbits.xen.org/xsa/advisory-298.html
PATCHhttp://xenbits.xen.org/xsa/advisory-298.html
ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2019-11/msg00037.html
ADVISORYhttp://www.openwall.com/lists/oss-security/2019/10/31/2
ADVISORYhttps://seclists.org/bugtraq/2020/Jan/21
ADVISORYhttps://security.gentoo.org/glsa/202003-56
ADVISORYhttps://www.debian.org/security/2020/dsa-4602
ADVISORYhttp://lists.opensuse.org/opensuse-security-announce/2019-11/msg00037.html
ADVISORYhttp://www.openwall.com/lists/oss-security/2019/10/31/2
ADVISORYhttps://seclists.org/bugtraq/2020/Jan/21
ADVISORYhttps://security.gentoo.org/glsa/202003-56
ADVISORYhttps://www.debian.org/security/2020/dsa-4602

All References (18)

→
http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00037.htmlMailing List · Third Party Advisory
→
http://www.openwall.com/lists/oss-security/2019/10/31/2Mailing List · Third Party Advisory
→
http://xenbits.xen.org/xsa/advisory-298.htmlPatch · Vendor Advisory
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2BQKX7M2RHCWDBKNPX4KEBI3MJIH6AYZ/
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I5WWPW4BSZDDW7VHU427XTVXV7ROOFFW/
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IZYATWNUGHRBG6I3TC24YHP5Y3J7I6KH/
→
https://seclists.org/bugtraq/2020/Jan/21Mailing List · Third Party Advisory
→
https://security.gentoo.org/glsa/202003-56Third Party Advisory
→
https://www.debian.org/security/2020/dsa-4602Third Party Advisory
→
http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00037.htmlMailing List · Third Party Advisory
→
http://www.openwall.com/lists/oss-security/2019/10/31/2Mailing List · Third Party Advisory
→
http://xenbits.xen.org/xsa/advisory-298.htmlPatch · Vendor Advisory
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2BQKX7M2RHCWDBKNPX4KEBI3MJIH6AYZ/
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I5WWPW4BSZDDW7VHU427XTVXV7ROOFFW/
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IZYATWNUGHRBG6I3TC24YHP5Y3J7I6KH/

Quick Facts

CVE IDCVE-2019-18425
CVSS Score9.8 / 10
SeverityCRITICAL
WeaknessCWE-269
CISA KEVNo
Affected4 vendor(s)
PublishedOct 31, 2019

Related CVEs (CWE-269)

CVE-2022-24783
10.0
CVE-2024-6240
10.0
CVE-2021-1388
10.0
CVE-2026-31852
10.0
CVE-2025-0505
10.0
CVE-2020-27655
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2019-18425 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.
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