CVE-2006-20001: Apache HTTP Server: mod_dav out of bounds read, or write of zero byte
Vulnerability summary
CVE-2006-20001 is a high (CVSS 7.5) Out-of-bounds Write vulnerability in apache software foundation apache http server. EPSS estimates a 3.58% chance of exploitation in the next 30 days, higher than 89.4% of scored vulnerabilities.
Severe, CVSS 7.5 (NVD); no exploitation reported by the 5 checked sources; EPSS 4% (FIRST, 03-11-2026)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 15 · Related 9Timeline
- 17-01-2023PublishedVulnerability first disclosed.
- 13-02-2025Last modifiedVulnerability information updated.
Description
A carefully crafted If: request header can cause a memory read, or write of a single zero byte, in a pool (heap) memory location beyond the header value sent. This could cause the process to crash. This issue affects Apache HTTP Server 2.4.54 and earlier.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · AlpineEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
3.58%
Chance of exploitation in the next 30 days
Percentile
89%
Versus all other CVEs
30-day change
Increase +0.04 pp
From 3.55% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Alpine1 product
- apache2< 2.4.55-r0
Apache1 product
- http_server< 2.4.55
Apache software foundation1 product
- apache http server≥ 2.4, ≤ 2.4.54
Debian1 product
- apache2< 2.4.55-1
Ubuntu1 product
- apache2All versions (No fix recorded) | < 2.4.18-2ubuntu3.17+esm8 | < 2.4.29-1ubuntu4.26 | < 2.4.41-4ubuntu3.13 | < 2.4.52-1ubuntu4.3
5 vendors · 5 products
