CVE-2019-7240: An issue was discovered in WinRing0x64.sys in Moo0 System Monitor 1.83

This month

HIGH 7.2DOWNGRADE

CVE-2019-7240 is a high-severity flaw (CVSS 7.2) affecting system monitor. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An issue was discovered in WinRing0x64.sys in Moo0 System Monitor 1.83. The vulnerable driver exposes a wrmsr instruction via IOCTL 0x9C402088 and does not properly filter the Model Specific Register (MSR). Allowing arbitrary MSR writes can lead to Ring-0 code execution and escalation of privileges.

Why this priority

High severity
Public exploit reference

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.2 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	High
User interaction	None
EPSS exploit chance	2.4% (top 16%)
CISA exploited list	No
Weakness	CWE-665
Published	2020-03-25
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: moo0

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2020-03-25 17:15 UTCPublished CVE record published
2026-06-17 02:40 UTCUpdated Record last modified

moo0 system monitor DOWNGRADE

Affected: 1.83

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.83

1. Check installed version

apt-cache policy system-monitor || rpm -q system-monitor || system-monitor --version

2. No fixed release: DOWNGRADE to a release before 1.83 (Debian / Ubuntu)

apt-cache madison system-monitor sudo apt install system-monitor=<VERSION_BEFORE_1.83> sudo apt-mark hold system-monitor

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list system-monitor sudo dnf downgrade system-monitor-<VERSION_BEFORE_1.83> sudo dnf versionlock add system-monitor

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2019-7240?

system monitor: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2019-7240 being exploited?

CVE-2019-7240 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2019-7240 affect?

CVE-2019-7240 affects system monitor. Severity is high (CVSS 7.2). An issue was discovered in WinRing0x64.sys in Moo0 System Monitor 1.83. The vulnerable driver exposes a wrmsr instruction via IOCTL 0x9C402088 and does not properly filter the Model Specific Register (MSR). Allowing arbitrary MSR writes can

How urgent is CVE-2019-7240?

Priority 51/100. High severity; Public exploit reference

References

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