CVE-2023-25824Public exploitNetwork attack vector

Service hang via timeout retry loop

Published Feb 23, 2023 · Updated Mar 10, 2025

Infinite-loop denial of service in mod_gnutls 0.9.0 through 0.12.0 allows remote attackers to hang Apache workers via TLS timeouts. The mgs_transport_read function converts APR_TIMEUP from mod_reqtimeout to EAGAIN, so gnutls_io_input_read treats the timeout as retryable and loops indefinitely. An unauthenticated client can hold a TLS connection idle until RequestReadTimeout expires, pinning a worker at full CPU; trace logging can also exhaust disk space.

CVSS severity7.5
High
EPSS probability1.09%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Infinite-loop denial of service in mod_gnutls 0.9.0 through 0.12.0 allows remote attackers to hang Apache workers via TLS timeouts. The mgs_transport_read function converts APR_TIMEUP from mod_reqtimeout to EAGAIN, so gnutls_io_input_read treats the timeout as retryable and loops indefinitely. An unauthenticated client can hold a TLS connection idle until RequestReadTimeout expires, pinning a worker at full CPU; trace logging can also exhaust disk space.

The record

CVE
CVE-2023-25824
Published
Feb 23, 2023
Updated
Mar 10, 2025
Vendor
airtower-luna
Product
mod_gnutls
Classifications
CWE-835, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 23, 2023CVE publishedPublication date reported by the CVE source.
  2. Mar 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=>= 0.9.0, < 0.12.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

airtower-luna · mod_gnutlsversion=>= 0.9.0, < 0.12.1

Published CVSS scores

7.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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 exploitPublished

Weakness, pattern, technique

CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')
T1499.004Application or System Exploitation

Public exploit references

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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