CVE-2018-12892: debian debian_linux
Vulnerability summary
CVE-2018-12892 is a critical (CVSS 9.9) vulnerability in debian debian_linux. EPSS estimates a 2.52% chance of exploitation in the next 30 days, higher than 84.8% of scored vulnerabilities.
Severe, CVSS 9.9 (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 6 · Related 5Timeline
- 02-07-2018PublishedVulnerability first disclosed.
- 05-08-2024Last modifiedVulnerability information updated.
Description
An issue was discovered in Xen 4.7 through 4.10.x. libxl fails to pass the readonly flag to qemu when setting up a SCSI disk, due to what was probably an erroneous merge conflict resolution. Malicious guest administrators or (in some situations) users may be able to write to supposedly read-only disk images. Only emulated SCSI disks (specified as "sd" in the libxl disk configuration, or an equivalent) are affected. IDE disks ("hd") are not affected (because attempts to make them readonly are rejected). Additionally, CDROM devices (that is, devices specified to be presented to the guest as CDROMs, regardless of the nature of the backing storage on the host) are not affected; they are always read only. Only systems using qemu-xen (rather than qemu-xen-traditional) as the device model version are vulnerable. Only systems using libxl or libxl-based toolstacks are vulnerable. (This includes xl, and libvirt with the libxl driver.) The vulnerability is present in Xen versions 4.7 and later. (In earlier versions, provided that the patch for XSA-142 has been applied, attempts to create read only disks are rejected.) If the host and guest together usually support PVHVM, the issue is exploitable only if the malicious guest administrator has control of the guest kernel or guest kernel command line.
CVSS metrics
5 scores · 4 sources · 2 versions- OSV · AlpineEcosystem advisory · calculated9.9CriticalCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- OSV · UbuntuEcosystem advisory · calculated9.9CriticalCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated9.9CriticalCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS trend
Probability
2.52%
Chance of exploitation in the next 30 days
Percentile
85%
Versus all other CVEs
30-day change
No change 0.00 pp
From 2.52% 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, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Debian2 products
- xen< 4.8.3+xsa267+shim4.10.1+xsa267-1+deb9u9
- debian_linuxEOL9.0
Alpine1 product
- xen≥ 4.7.0, < 4.11.0-r0 | ≥ 4.7.0, < 4.7.6-r0 | ≥ 4.7.0, < 4.8.4-r0 | ≥ 4.7.0, < 4.9.3-r0 | ≥ 4.7.0, < 4.10.1-r3
Ubuntu1 product
- xenAll versions (No fix recorded)
Xen1 product
- xen≥ 4.7.0, ≤ 4.10.1
4 vendors · 5 products
