CVE-2025-53634Network attack vector

Unauthenticated service interruption via missing header timeout

Published Jul 10, 2025 · Updated Jul 10, 2025

Denial of service in CTFer.io Chall-Manager before 0.1.4 allows remote attackers to interrupt its HTTP Gateway via Slowloris requests. The newHTTPServer function constructs the Go HTTP server without ReadHeaderTimeout, allowing incomplete headers to retain connections and consume server resources indefinitely. No authentication is required, but exposure depends on network access to a service that the vendor recommends isolating deep within trusted infrastructure.

CVSS severity8.7
High
EPSS probability0.46%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in CTFer.io Chall-Manager before 0.1.4 allows remote attackers to interrupt its HTTP Gateway via Slowloris requests. The newHTTPServer function constructs the Go HTTP server without ReadHeaderTimeout, allowing incomplete headers to retain connections and consume server resources indefinitely. No authentication is required, but exposure depends on network access to a service that the vendor recommends isolating deep within trusted infrastructure.

The record

CVE
CVE-2025-53634
Published
Jul 10, 2025
Updated
Jul 10, 2025
Vendor
CTFer.io
Product
Chall-Manager
Classifications
CWE-770, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 10, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 10, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=< 0.1.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

CTFer.io · Chall-Managerversion=< 0.1.4

Published CVSS scores

8.7GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
T1499.003Network Denial of Service: Application Exhaustion Flood

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

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Your stack

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