CVE-2019-18425: debian debian_linux Improper Privilege Management
Vulnerability summary
CVE-2019-18425 is a critical (CVSS 9.8) Improper Privilege Management vulnerability in debian debian_linux. EPSS estimates a 2.55% chance of exploitation in the next 30 days, higher than 85% of scored vulnerabilities.
Severe, CVSS 9.8 (NVD); no exploitation reported by the 5 checked sources; EPSS 3% (FIRST, 03-11-2026)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 11 · Related 9Timeline
- 31-10-2019PublishedVulnerability first disclosed.
- 05-08-2024Last modifiedVulnerability information updated.
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.
CVSS metrics
5 scores · 4 sources · 2 versions- OSV · AlpineEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · UbuntuEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
2.55%
Chance of exploitation in the next 30 days
Percentile
85%
Versus all other CVEs
30-day change
No change 0.00 pp
From 2.55% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Debian2 products
- xen< 4.11.3+24-g14b62ab3e5-1
- debian_linuxEOL9.0 | 10.0
Alpine1 product
- xen< 4.12.1-r1 | < 4.13.0-r0 | < 4.10.4-r1 | < 4.11.2-r1
Fedoraproject1 product
- fedoraEOL29 | 30 | 31
Opensuse1 product
- leapEOL15.0
Ubuntu1 product
- xenAll versions (No fix recorded)
Xen1 product
- xen≤ 4.12.1
6 vendors · 7 products
References
14 links- www.openwall.com/lists/oss-security/2019/10/31/2Mailing ListX Refsource MLISTREPORTThird Party Advisory
- lists.opensuse.org/opensuse-security-announce/2019-11/msg00037.htmlVendor AdvisoryX Refsource SUSEMailing ListThird Party Advisory
