CVE-2021-43457: An Unquoted Service Path vulnerability exists in bVPN 2.5.1 via a specially crafted file in the waselvpnserv s

Routine

HIGH 7.8DOWNGRADE

CVE-2021-43457 is a high-severity flaw (CVSS 7.8) affecting bvpn. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An Unquoted Service Path vulnerability exists in bVPN 2.5.1 via a specially crafted file in the waselvpnserv service path.

Why this priority

High severity

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

Risk facts

CVSS score	7.8 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.3% (top 75%)
CISA exploited list	No
Weakness	CWE-428
Published	2022-04-04
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: bvpn

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

Am I affected?

Timeline

2022-04-04 15:15 UTCPublished CVE record published
2026-06-17 04:11 UTCUpdated Record last modified

bvpn bvpn DOWNGRADE

Affected: 2.5.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.5.1

1. Check installed version

apt-cache policy bvpn || rpm -q bvpn || bvpn --version

2. No fixed release: DOWNGRADE to a release before 2.5.1 (Debian / Ubuntu)

apt-cache madison bvpn sudo apt install bvpn=<VERSION_BEFORE_2.5.1> sudo apt-mark hold bvpn

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

dnf --showduplicates list bvpn sudo dnf downgrade bvpn-<VERSION_BEFORE_2.5.1> sudo dnf versionlock add bvpn

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-2021-43457?

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

Is CVE-2021-43457 being exploited?

CVE-2021-43457 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-2021-43457 affect?

CVE-2021-43457 affects bvpn. Severity is high (CVSS 7.8). An Unquoted Service Path vulnerability exists in bVPN 2.5.1 via a specially crafted file in the waselvpnserv service path.

How urgent is CVE-2021-43457?

Priority 33/100. High severity

References

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