CVE-2021-32541Network attack vector

Unauthenticated forced logout via username flooding

Published May 28, 2021 · Updated Sep 17, 2024

Improper session management in SysJust CTS Web releases through March 25, 2021 allows remote attackers to force logged-in users offline. The connection-authentication path improperly processes a large volume of valid usernames by terminating active sessions associated with those accounts. No login or user interaction is required; the bounded consequence is loss of service for targeted logged-in accounts, not data access or modification.

CVSS severity5.3
Medium
EPSS probability1.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper session management in SysJust CTS Web releases through March 25, 2021 allows remote attackers to force logged-in users offline. The connection-authentication path improperly processes a large volume of valid usernames by terminating active sessions associated with those accounts. No login or user interaction is required; the bounded consequence is loss of service for targeted logged-in accounts, not data access or modification.

The record

CVE
CVE-2021-32541
Published
May 28, 2021
Updated
Sep 17, 2024
Vendor
SysJust
Product
CTS Web
Classifications
CWE-287, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 28, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <=released 2021.3.25

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

SysJust · CTS Webversion=unspecified <=released 2021.3.25

Published CVSS scores

5.3TWCERT/CCCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-287Improper Authentication
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo