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CVE-2006-20001· NVD / CVE Program· CNA apache

Apache HTTP Server: mod_dav out of bounds read, or write of zero byte

Noroxi assessment

Priority: Monitor (action score 31/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 3.5% (FIRST EPSS); higher than 89% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: httpd (AlmaLinux:8) 2.4.37-51.module_el8.7.0+3405+9516b832.1; httpd-devel (AlmaLinux:8) 2.4.37-51.module_el8.7.0+3405+9516b832.1; httpd-filesystem (AlmaLinux:8) 2.4.37-51.module_el8.7.0+3405+9516b832.1.
  • Mentioned 4 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to httpd (AlmaLinux:8) 2.4.37-51.module_el8.7.0+3405+9516b832.1; httpd-devel (AlmaLinux:8) 2.4.37-51.module_el8.7.0+3405+9516b832.1; httpd-filesystem (AlmaLinux:8) 2.4.37-51.module_el8.7.0+3405+9516b832.1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

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.

HighCVSS 7.5 · v3.1—Proof of concept Fix available
Published
Jan 17, 2023
Updated
Jun 16, 2026
EPSS
3.5% · 89th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 3.5%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2006-20001

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
apachehttp server

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Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • apache http serverbefore 2.4.55

Versions reported by the vendor

Affected version ranges reported by the assigning authority (apache). Independent of NVD's CPE analysis and usually ahead of it.

  • Apache Software Foundation Apache HTTP Server

    • 2.4 and later · up to and including 2.4.54affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:8httpdbefore 2.4.37-51.module_el8.7.0+3405+9516b832.12.4.37-51.module_el8.7.0+3405+9516b832.1
AlmaLinux:8httpd-develbefore 2.4.37-51.module_el8.7.0+3405+9516b832.12.4.37-51.module_el8.7.0+3405+9516b832.1
AlmaLinux:8httpd-filesystembefore 2.4.37-51.module_el8.7.0+3405+9516b832.12.4.37-51.module_el8.7.0+3405+9516b832.1
AlmaLinux:8httpd-manualbefore 2.4.37-51.module_el8.7.0+3405+9516b832.12.4.37-51.module_el8.7.0+3405+9516b832.1
AlmaLinux:8httpd-toolsbefore 2.4.37-51.module_el8.7.0+3405+9516b832.12.4.37-51.module_el8.7.0+3405+9516b832.1
AlmaLinux:8mod_http2before 1.15.7-5.module_el8.6.0+2872+fe0ff7aa1.15.7-5.module_el8.6.0+2872+fe0ff7aa
AlmaLinux:8mod_http2before 1.15.7-5.module_el8.6.0+3031+fb177b091.15.7-5.module_el8.6.0+3031+fb177b09
AlmaLinux:8mod_ldapbefore 2.4.37-51.module_el8.7.0+3405+9516b832.12.4.37-51.module_el8.7.0+3405+9516b832.1
AlmaLinux:8mod_mdbefore 1:2.0.8-8.module_el8.6.0+2872+fe0ff7aa1:2.0.8-8.module_el8.6.0+2872+fe0ff7aa
AlmaLinux:8mod_mdbefore 1:2.0.8-8.module_el8.6.0+3031+fb177b091:2.0.8-8.module_el8.6.0+3031+fb177b09
AlmaLinux:8mod_proxy_htmlbefore 1:2.4.37-51.module_el8.7.0+3405+9516b832.11:2.4.37-51.module_el8.7.0+3405+9516b832.1
AlmaLinux:8mod_sessionbefore 2.4.37-51.module_el8.7.0+3405+9516b832.12.4.37-51.module_el8.7.0+3405+9516b832.1
AlmaLinux:8mod_sslbefore 1:2.4.37-51.module_el8.7.0+3405+9516b832.11:2.4.37-51.module_el8.7.0+3405+9516b832.1
AlmaLinux:9httpdbefore 2.4.53-7.el9_1.12.4.53-7.el9_1.1
AlmaLinux:9httpd-corebefore 2.4.53-7.el9_1.12.4.53-7.el9_1.1
AlmaLinux:9httpd-develbefore 2.4.53-7.el9_1.12.4.53-7.el9_1.1
AlmaLinux:9httpd-filesystembefore 2.4.53-7.el9_1.12.4.53-7.el9_1.1
AlmaLinux:9httpd-manualbefore 2.4.53-7.el9_1.12.4.53-7.el9_1.1
AlmaLinux:9httpd-toolsbefore 2.4.53-7.el9_1.12.4.53-7.el9_1.1
AlmaLinux:9mod_ldapbefore 2.4.53-7.el9_1.12.4.53-7.el9_1.1
AlmaLinux:9mod_luabefore 2.4.53-7.el9_1.12.4.53-7.el9_1.1
AlmaLinux:9mod_proxy_htmlbefore 1:2.4.53-7.el9_1.11:2.4.53-7.el9_1.1
AlmaLinux:9mod_sessionbefore 2.4.53-7.el9_1.12.4.53-7.el9_1.1
AlmaLinux:9mod_sslbefore 1:2.4.53-7.el9_1.11:2.4.53-7.el9_1.1

+96

Same product

apache: all records

Other highest-scoring records for the same primary product.

  • CVE-2021-42013Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773)KEV
    99Now
  • CVE-2021-41773Path traversal and file disclosure vulnerability in Apache HTTP Server 2.4.49KEV
    99Now
  • CVE-2024-38475Apache HTTP Server weakness in mod_rewrite when first segment of substitution matches filesystem path.KEV
    96Now
  • CVE-2019-0211In Apache HTTP Server 2.4 releases 2.4.17 to 2.4.38, with MPM event, worker or prefork, code executing in less-privileged child processes orKEV
    81Now
  • CVE-2021-44790Possible buffer overflow when parsing multipart content in mod_lua of Apache HTTP Server 2.4.51 and earlier
    68This week
  • CVE-2010-0425modules/arch/win32/mod_isapi.c in mod_isapi in the Apache HTTP Server 2.0.37 through 2.0.63, 2.2.0 through 2.2.14, and 2.3.x before 2.3.7, w
    68This week

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
almalinux:httpd2.4.37-51.module_el8.7.0+3405+9516b832.1 · AlmaLinux:8Package registry (OSV)
almalinux:httpd-core2.4.53-7.el9_1.1 · AlmaLinux:9Package registry (OSV)
almalinux:httpd-devel2.4.37-51.module_el8.7.0+3405+9516b832.1 · AlmaLinux:8Package registry (OSV)
almalinux:httpd-filesystem2.4.37-51.module_el8.7.0+3405+9516b832.1 · AlmaLinux:8Package registry (OSV)
almalinux:httpd-manual2.4.37-51.module_el8.7.0+3405+9516b832.1 · AlmaLinux:8Package registry (OSV)
almalinux:httpd-tools2.4.37-51.module_el8.7.0+3405+9516b832.1 · AlmaLinux:8Package registry (OSV)
almalinux:mod_http21.15.7-5.module_el8.6.0+2872+fe0ff7aa · AlmaLinux:8Package registry (OSV)
almalinux:mod_ldap2.4.37-51.module_el8.7.0+3405+9516b832.1 · AlmaLinux:8Package registry (OSV)
almalinux:mod_md1:2.0.8-8.module_el8.6.0+2872+fe0ff7aa · AlmaLinux:8Package registry (OSV)
almalinux:mod_proxy_html1:2.4.37-51.module_el8.7.0+3405+9516b832.1 · AlmaLinux:8Package registry (OSV)
almalinux:mod_session2.4.37-51.module_el8.7.0+3405+9516b832.1 · AlmaLinux:8Package registry (OSV)
almalinux:mod_ssl1:2.4.37-51.module_el8.7.0+3405+9516b832.1 · AlmaLinux:8Package registry (OSV)
alpine:apache22.4.55-r0 · Alpine:v3.14Package registry (OSV)
debian:apache22.4.55-1 · Debian:12Package registry (OSV)
opensuse:apache22.4.51-150400.6.6.1 · openSUSE:Leap 15.4Package registry (OSV)
red hat:httpd0:2.4.37-51.module+el8.7.0+18026+7b169787.1 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:httpd-debuginfo0:2.4.37-51.module+el8.7.0+18026+7b169787.1 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:httpd-debugsource0:2.4.37-51.module+el8.7.0+18026+7b169787.1 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:httpd-devel0:2.4.37-51.module+el8.7.0+18026+7b169787.1 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:httpd-filesystem0:2.4.37-51.module+el8.7.0+18026+7b169787.1 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:httpd-manual0:2.4.37-51.module+el8.7.0+18026+7b169787.1 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:httpd-tools0:2.4.37-51.module+el8.7.0+18026+7b169787.1 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:httpd-tools-debuginfo0:2.4.37-51.module+el8.7.0+18026+7b169787.1 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:mod_http20:1.15.7-5.module+el8.6.0+13996+01710940 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:mod_http2-debuginfo0:1.15.7-5.module+el8.6.0+13996+01710940 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:mod_http2-debugsource0:1.15.7-5.module+el8.6.0+13996+01710940 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
red hat:mod_ldap0:2.4.37-51.module+el8.7.0+18026+7b169787.1 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
rocky linux:httpd0:2.4.37-51.module+el8.7.0+1059+126e9251 · Rocky Linux:8Package registry (OSV)
rocky linux:mod_http20:1.15.7-5.module+el8.6.0+823+f143cee1 · Rocky Linux:8Package registry (OSV)
rocky linux:mod_md1:2.0.8-8.module+el8.5.0+695+1fa8055e · Rocky Linux:8Package registry (OSV)

+2

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:02023-02-07

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. First PoC+20 d
  3. TodayOct 13, 2026+1365 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-787 · Out-of-bounds Write

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records