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Vulnerabilities

Vulnerability · CVE-2006-20001

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.

Published Jan 17, 2023 · catalog updated Oct 22, 2026 · A carefully crafted If:

Check if you run it

No confirmed exploitation is on record for CVE-2006-20001. EPSS is 3.55%. Act only if a listed version of A carefully crafted If: is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (A carefully crafted If:).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
3.55%
Remediation
Advisory link
Affected products
Alpine:v3.14 apache2 · Alpine:v3.15 apache2 · Alpine:v3.16 apache2 · Alpine:v3.17 apache2

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • Alpine:v3.14 apache20 → 2.4.55-r0
  • Alpine:v3.15 apache20 → 2.4.55-r0
  • Alpine:v3.16 apache20 → 2.4.55-r0
  • Alpine:v3.17 apache20 → 2.4.55-r0

How to fix CVE-2006-20001

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2006-20001. EPSS is 3.55%. Act only if a listed version of A carefully crafted If: is installed.

Which versions are affected?

Compare what you have installed with 0 → 2.4.55-r0. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 3.55%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Jan 17, 2023 · OpenSSF OSV / OSV Scanner

    Detected

    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.

  2. Oct 21, 2026 · OpenSSF OSV / OSV Scanner

    Fix available

    apache2 fixed in 2.4.55-r0; apache2 fixed in 2.4.55-r0; apache2 fixed in 2.4.55-r0; apache2 fixed in 2.4.55-r0

  3. Oct 21, 2026 · OpenSSF OSV / OSV Scanner

    Fix available

    apache2 fixed in 2.4.55-r0

  4. Oct 21, 2026 · OpenSSF OSV / OSV Scanner

    Updated

    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.

  5. Oct 22, 2026 · OpenSSF OSV / OSV Scanner

    Updated

    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.

Sources

  • CVE.orgVulnerability recordCVE-2006-20001

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2006-20001

    30-day exploitation probability 3.55%

    first.org
  • OpenSSF OSV / OSV ScannerPackage advisoryALPINE-CVE-2006-20001
    osv.dev
  • Trivy Vulnerability DBPackage advisoryALPINE-CVE-2006-20001

    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.

    osv.dev

References

Freshness

Last verified in this catalog Oct 23, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

CVE-2006-20001: A carefully crafted If: request header can cause a… · ZeroDay Findings