CVE-2021-4433: A vulnerability was found in Karjasoft Sami HTTP Server 2.0

This week

MEDIUM 5.3REMOTEDOWNGRADE

CVE-2021-4433 is a medium-severity flaw (CVSS 5.3) affecting sami http server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A vulnerability was found in Karjasoft Sami HTTP Server 2.0. It has been classified as problematic. Affected is an unknown function of the component HTTP HEAD Rrequest Handler. The manipulation leads to denial of service. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used. The identifier of this vulnerability is VDB-250836.

Why this priority

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	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.3% (top 30%)
CISA exploited list	No
Weakness	CWE-404
Published	2024-01-18
Last modified	2026-06-17

Publisher (CNA): VulDB · Vendor: karjasoft

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

Am I affected?

Timeline

2024-01-18 01:15 UTCPublished CVE record published
2026-06-17 04:19 UTCUpdated Record last modified

karjasoft sami http server DOWNGRADE

Affected: 2.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.0

1. Check installed version

apt-cache policy sami-http-server || rpm -q sami-http-server || sami-http-server --version

2. No fixed release: DOWNGRADE to a release before 2.0 (Debian / Ubuntu)

apt-cache madison sami-http-server sudo apt install sami-http-server=<VERSION_BEFORE_2.0> sudo apt-mark hold sami-http-server

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

dnf --showduplicates list sami-http-server sudo dnf downgrade sami-http-server-<VERSION_BEFORE_2.0> sudo dnf versionlock add sami-http-server

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-2021-4433?

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

Is CVE-2021-4433 being exploited?

CVE-2021-4433 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-2021-4433 affect?

CVE-2021-4433 affects sami http server. Severity is medium (CVSS 5.3). A vulnerability was found in Karjasoft Sami HTTP Server 2.0. It has been classified as problematic. Affected is an unknown function of the component HTTP HEAD Rrequest Handler. The manipulation leads to denial of service. It is possible to

How urgent is CVE-2021-4433?

Priority 46/100. Public exploit reference; Remotely exploitable, no login, no user action

References

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