CVE-2021-40903: A vulnerability in Antminer Monitor 0.50.0 exists because of backdoor or misconfiguration inside a settings fi

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CRITICAL 9.8REMOTEDOWNGRADE

CVE-2021-40903 is a critical-severity flaw (CVSS 9.8) affecting antminer monitor. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A vulnerability in Antminer Monitor 0.50.0 exists because of backdoor or misconfiguration inside a settings file in flask server. Settings file has a predefined secret string, which would be randomly generated, however it is static.

Why this priority

Critical severity
EPSS top 8%: very likely to be exploited
Public exploit reference
Remotely exploitable, no login, no user action

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

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	4.5% (top 8%)
CISA exploited list	No
Weakness	CWE-798
Published	2022-06-17
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: antminer monitor project

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

Am I affected?

Timeline

2022-06-17 14:15 UTCPublished CVE record published
2026-06-17 04:07 UTCUpdated Record last modified

antminer monitor project antminer monitor DOWNGRADE

Affected: 0.50.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.50.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 0.50.0 (Debian / Ubuntu)

apt-cache madison antminer-monitor sudo apt install antminer-monitor=<VERSION_BEFORE_0.50.0> sudo apt-mark hold antminer-monitor

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

dnf --showduplicates list antminer-monitor sudo dnf downgrade antminer-monitor-<VERSION_BEFORE_0.50.0> sudo dnf versionlock add antminer-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-2021-40903?

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

Is CVE-2021-40903 being exploited?

CVE-2021-40903 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-2021-40903 affect?

CVE-2021-40903 affects antminer monitor. Severity is critical (CVSS 9.8). A vulnerability in Antminer Monitor 0.50.0 exists because of backdoor or misconfiguration inside a settings file in flask server. Settings file has a predefined secret string, which would be randomly generated, however it is static.

How urgent is CVE-2021-40903?

Priority 67/100. Critical severity; EPSS top 8%: very likely to be exploited; Public exploit reference; Remotely exploitable, no login, no user action

Software pages

Flask vulnerabilities

References

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