CVE-2021-40858 is a medium-severity flaw (CVSS 4.9) affecting compact 5500r ip firmware, compact 5200r ip firmware, compact 5000r ip firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Auerswald COMpact 5500R devices before 8.2B allow Arbitrary File Disclosure. A sub-admin can read the cleartext Admin password via the fileName=../../etc/passwd substring.
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
Published CVE record published
Updated Record last modified
auerswald compact 5500r ip firmware UPGRADE
Affected: <= 8.0b
Fixed in: newer than 8.0b
Safe to downgrade to: no unaffected older release
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
auerswald compact 5200r ip firmware UPGRADE
Affected: <= 8.0b
Fixed in: newer than 8.0b
Safe to downgrade to: no unaffected older release
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
auerswald compact 5000r ip firmware UPGRADE
Affected: <= 8.0b
Fixed in: newer than 8.0b
Safe to downgrade to: no unaffected older release
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
auerswald compact 4000 ip firmware UPGRADE
Affected: <= 8.0b
Fixed in: newer than 8.0b
Safe to downgrade to: no unaffected older release
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
auerswald commander 6000r ip firmware UPGRADE
Affected: <= 8.0b
Fixed in: newer than 8.0b
Safe to downgrade to: no unaffected older release
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
auerswald commander 6000rx ip firmware UPGRADE
Affected: <= 8.0b
Fixed in: newer than 8.0b
Safe to downgrade to: no unaffected older release
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
Verify at the official sourceNVD · 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-2021-40858?
compact 5500r ip firmware: upgrade to newer than 8.0b; compact 5200r ip firmware: upgrade to newer than 8.0b; compact 5000r ip firmware: upgrade to newer than 8.0b. Exact commands for each OS are on this page.
Is CVE-2021-40858 being exploited?
CVE-2021-40858 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-2021-40858 affect?
CVE-2021-40858 affects compact 5500r ip firmware, compact 5200r ip firmware, compact 5000r ip firmware. Severity is medium (CVSS 4.9). Auerswald COMpact 5500R devices before 8.2B allow Arbitrary File Disclosure. A sub-admin can read the cleartext Admin password via the fileName=../../etc/passwd substring.
How urgent is CVE-2021-40858?
Priority 43/100. Public exploit reference
Related CVEs
CVE-2021-40857HIGH 8.8UPGRADEUPGRADE Auerswald COMpact 5500R devices before 8.2B allow Privilege Escalation via the passwd=1 substring.
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