CVE-2020-25691Network attack vector

Server crash via oversized file modification date

Published Apr 1, 2022 · Updated Aug 4, 2024

Denial of service in darkhttpd 1.13-1 and earlier allows remote attackers to crash the server by requesting a file dated year 10,000 or later. The rfc1123_date function in darkhttpd.c mishandles the out-of-range modification time while generating the HTTP date value, terminating the process. The request requires no authentication, but the server must expose a file whose modification time is in year 10,000 or later.

CVSS severity7.5
High
EPSS probability1.32%
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 darkhttpd 1.13-1 and earlier allows remote attackers to crash the server by requesting a file dated year 10,000 or later. The rfc1123_date function in darkhttpd.c mishandles the out-of-range modification time while generating the HTTP date value, terminating the process. The request requires no authentication, but the server must expose a file whose modification time is in year 10,000 or later.

The record

CVE
CVE-2020-25691
Published
Apr 1, 2022
Updated
Aug 4, 2024
Vendor
Emil Mikulic
Product
darkhttpd
Classifications
CWE-755, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 1, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record 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=versions up to and including darkhttpd-1.13-1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Emil Mikulic · darkhttpdversion=versions up to and including darkhttpd-1.13-1

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P

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.

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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-755Improper Handling of Exceptional Conditions
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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