CVE-2023-54337: Sysax Multi Server 6.95 contains a denial of service vulnerability in the administrative password field that a

This week

CRITICAL 9.1REMOTEDOWNGRADE

CVE-2023-54337 is a critical-severity flaw (CVSS 9.1) affecting multi server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Sysax Multi Server 6.95 contains a denial of service vulnerability in the administrative password field that allows attackers to crash the application. Attackers can overwrite the password field with 800 bytes of repeated characters to trigger an application crash and disrupt server functionality.

Why this priority

Critical severity
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	9.1 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.5% (top 55%)
CISA exploited list	No
Weakness	CWE-1284
Published	2026-01-13
Last modified	2026-06-17

Publisher (CNA): VulnCheck · Vendor: sysax

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

Am I affected?

Timeline

2026-01-13 23:16 UTCPublished CVE record published
2026-06-17 06:47 UTCUpdated Record last modified

sysax multi server DOWNGRADE

Affected: 6.95

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.95

1. Check installed version

apt-cache policy multi-server || rpm -q multi-server || multi-server --version

2. No fixed release: DOWNGRADE to a release before 6.95 (Debian / Ubuntu)

apt-cache madison multi-server sudo apt install multi-server=<VERSION_BEFORE_6.95> sudo apt-mark hold multi-server

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

dnf --showduplicates list multi-server sudo dnf downgrade multi-server-<VERSION_BEFORE_6.95> sudo dnf versionlock add multi-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-2023-54337?

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

Is CVE-2023-54337 being exploited?

CVE-2023-54337 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-2023-54337 affect?

CVE-2023-54337 affects multi server. Severity is critical (CVSS 9.1). Sysax Multi Server 6.95 contains a denial of service vulnerability in the administrative password field that allows attackers to crash the application. Attackers can overwrite the password field with 800 bytes of repeated characters to trig

How urgent is CVE-2023-54337?

Priority 53/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2024-53459 MEDIUM 5.4 DOWNGRADE Sysax Multi Server 6.99 is vulnerable to Cross Site Scripting (XSS) via the /scgi?sid parameter.
CVE-2024-53458 HIGH 7.5 DOWNGRADE Sysax Multi Server 6.99 is vulnerable to a denial of service (DoS) condition when processing specially crafted
CVE-2013-10065 HIGH 7.5 DOWNGRADE A denial-of-service vulnerability exists in Sysax Multi-Server version 6.10 via its SSH daemon
CVE-2012-10060 CRITICAL 9.8 UPGRADE Sysax Multi Server versions prior to 5.55 contain a stack-based buffer overflow in its SSH service

References

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