CVE-2006-3747

HIGHCVSS v2 · 7.67.6
EchelonGraph scoreLOW confidence

“—” beside the score: it is equal to NVD's CVSS v2 base score.

This CVE was only ever scored under CVSS v2.0. NVD CVSS v2.0 base 7.6 — NVD rates that HIGH (NVD's v2 bands: LOW 0.0–3.9 / MEDIUM 4.0–6.9 / HIGH 7.0–10.0; no CRITICAL band). Vector AV:N/AC:H/Au:N/C:C/I:C/A:C. CVSS v2 is an older, coarser metric than v3.1/v4.0 (no Scope, no User Interaction, no Attack Requirements), so it is not directly comparable to a v3 or v4 score. NVD has never re-scored this record under v3. EPSS predicts 97% exploitation probability in the next 30 days; it does not lift the v2 base. EPSS sets EG Risk's exploitation input. Confidence: LOW.

Triggered by: NVD CVSS v2.0 (legacy fallback)
Sources: NVD CVSS v2.0
Trending — 3 sources updated this weekWeaponized

Also known asEUVD-2006-3741 (ENISA EUVD) · GHSA-47q7-qpgp-938j (GitHub Security Advisories)Source: ENISA EUVD

7.6EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • 9 internet-facing services (distinct ip:port) on record running an affected version — derived from Shodan data (© Shodan); a patched service can stay counted while its port stays open
  • High exploitation likelihood — EPSS 97%
  • Public exploit code is available (Metasploit, Exploit-DB, marked verified by Exploit-DB, other public proof-of-concept code)
CISA-KEV: Not listedEPSS PROB: 97%CVSS v2: 7.6Exploit: Metasploit · Exploit-DB (verified) · other public PoCExposed services: 9

A fix is available — apply it.

Off-by-one error in the ldap scheme handling in the Rewrite module (mod_rewrite) in Apache 1.3 from 1.3.28, 2.0.46 and other versions before 2.0.59, and 2.2, when RewriteEngine is enabled, allows remote attackers to cause a denial of service (application crash) and possibly execute arbitrary code via crafted URLs that are not properly handled using certain rewrite rules.

Internet exposure · derived from Shodan data

9 internet-facing services (distinct ip:port) on record running a version that maps to CVE-2006-3747, in our KEV-Exposure radar’s Shodan-derived sample.

across 6 countries (United States, Japan, Canada, China, Korea, Republic of)top: http_server
See the KEV-Exposure radar →Derived from Shodan data. Shodan data is owned by Shodan, which holds its copyright (© Shodan). EchelonGraph claims no ownership of it or copyright in it. Aggregate, host-redacted.

How it counts: every 12 hours, when Shodan query credits allow, the radar runs one Shodan query per tracked product, reads up to 100 ip:port services per query, and keeps a service when its banner version matches a CISA-KEV or high-EPSS CVE; a service is dropped when neither a search nor a Shodan InternetDB port re-check has refreshed it for 21 days. A re-check that finds the port still listed by Shodan InternetDB refreshes the service without re-reading the banner, so a patched service can stay counted while its port stays open. A count is a banner-version inference over a sample, not an exploit test and not an internet-wide census, and the unit is a service, not a machine: a machine answering on two ports counts twice.

CVSS v2.0 (legacy)
7.6HIGHNVD never assigned a CVSS v3 rating to this CVE
EG Score
7.6HIGHlow confidence
EG Risk
73
EG Risk 73/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity76% × 45%
Impact severity (EG Severity): CVSS 7.6 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation97% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's BOD 26-04 default: no one has published Automatable for this CVE, and CISA treats it as “no” for a CVE not in KEV.
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.
Exploitation public PoC (exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
97%
EPSS %ILE
99th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (7.6): severity, escalated by confirmed exploitation. This CVE's 7.6 is its impact severity (EG Severity), not escalated.

EG Severity
7.6 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v2.0 · CVSS v2.0AV:N/AC:H/Au:N/C:C/I:C/A:C
EG Likelihood
97% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-25). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track* at medium mission impactTrack at low, Track* at medium and Attend at high mission impact.CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low, Track* at medium and Attend at high mission impact.

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

July 28, 2006

Last Modified

April 16, 2026

References (90)

15 of 90 shown · show the other 75

Patch Availability(1)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntuapache2-mpm-threadpool (2.0.54-5ubuntu4.1) @ breezy2026-07-23ubuntu

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(6 across 5 ecosystems)
Debian:3.1(2)
PackageVulnerable rangeFix by version rangeDependents
apache1.3.33-6, 1.3.33-6sarge1
  • every version up to 1.3.33-6sarge2: fixed in 1.3.33-6sarge2
—
apache22.0.54-4, 2.0.54-5
  • every version up to 2.0.54-5sarge1: fixed in 2.0.54-5sarge1
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.0.55-4.1: fixed in 2.0.55-4.1
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.0.55-4.1: fixed in 2.0.55-4.1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.0.55-4.1: fixed in 2.0.55-4.1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
apache2—
  • every version up to 2.0.55-4.1: fixed in 2.0.55-4.1
—

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 4× in last 7d / 13× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 7 repeat rows among the latest 67 are merged into the row they repeat.

  1. 2026-10-25 20:41 UTCEG score recompute
  2. 2026-10-25 16:25 UTCEPSS rescoreEPSS 97% · 99th percentile
  3. 2026-10-24 21:25 UTCOSV refresh
  4. 2026-10-21 16:25 UTCEPSS rescoreEPSS 97% · 99th percentile
  5. 2026-10-18 12:07 UTCEG score recompute
  6. 2026-10-17 16:25 UTCEPSS rescoreEPSS 97% · 99th percentile
  7. 2026-10-15 16:25 UTCEPSS rescoreEPSS 97% · 99th percentile
  8. 2026-10-14 16:25 UTCEPSS rescoreEPSS 97% · 99th percentile
  9. 2026-10-12 22:04 UTCEG score recompute
  10. 2026-10-12 02:13 UTCEG score recompute
  11. 2026-10-07 23:36 UTCEPSS rescoreEPSS 97% · 99th percentile
  12. 2026-10-01 02:10 UTCOSV refresh
  13. 2026-09-29 03:01 UTCEG score recompute
  14. 2026-09-18 19:20 UTCEPSS rescoreEPSS 97% · 99th percentile
  15. 2026-09-12 05:40 UTCOSV refresh
  16. 2026-09-05 15:21 UTCEPSS rescoreEPSS 97% · 99th percentile
  17. 2026-08-24 11:12 UTCOSV refresh
  18. 2026-08-08 07:26 UTCOSV refresh
  19. 2026-07-26 13:29 UTCEG score recomputeAssessed again: 7.6 HIGH
  20. 2026-07-23 00:51 UTCEG score recompute
  21. 2026-07-23 00:39 UTCVendor advisory
  22. 2026-07-23 00:39 UTCGHSA enrichmentGHSA-47q7-qpgp-938j · GitHub severity HIGH
  23. 2026-07-23 00:36 UTCVendor advisory
  24. 2026-07-23 00:36 UTCGHSA enrichmentGHSA-47q7-qpgp-938j · GitHub severity HIGH
  25. 2026-07-23 00:36 UTCVendor advisory
Show 35 more
  1. 2026-07-23 00:36 UTCGHSA enrichmentGHSA-47q7-qpgp-938j · GitHub severity HIGH
  2. 2026-07-23 00:34 UTCVendor advisory
  3. 2026-07-23 00:34 UTCGHSA enrichmentGHSA-47q7-qpgp-938j · GitHub severity HIGH
  4. 2026-07-23 00:33 UTCVendor advisory
  5. 2026-07-23 00:33 UTCGHSA enrichmentGHSA-47q7-qpgp-938j · GitHub severity HIGH
  6. 2026-07-23 00:33 UTCVendor advisory
  7. 2026-07-23 00:32 UTCGHSA enrichmentGHSA-47q7-qpgp-938j · GitHub severity HIGH
  8. 2026-07-23 00:30 UTCGHSA enrichmentGHSA-47q7-qpgp-938j · GitHub severity HIGH
  9. 2026-07-23 00:30 UTCEG score recompute▼ 9.00
  10. 2026-07-22 23:55 UTCEG score recompute
  11. 2026-07-22 21:35 UTCEG score recompute
  12. 2026-07-09 19:03 UTCEPSS rescoreEPSS 96% · 99th percentile
  13. 2026-07-08 20:39 UTCOSV refresh
  14. 2026-07-02 14:00 UTCEPSS rescoreEPSS 96% · 99th percentile
  15. 2026-06-25 13:46 UTCEPSS rescoreEPSS 96% · 99th percentile
  16. 2026-06-24 14:01 UTCEPSS rescoreEPSS 96% · 99th percentile
  17. 2026-06-23 21:29 UTCEPSS rescoreEPSS 96% · 99th percentile
  18. 2026-06-20 08:12 UTCOSV refresh
  19. 2026-06-15 17:44 UTCEPSS rescoreEPSS 96% · 99th percentile
  20. 2026-06-13 22:56 UTCEPSS rescoreEPSS 90% · 99th percentile
  21. 2026-06-10 22:14 UTCEPSS rescoreEPSS 90% · 99th percentile
  22. 2026-06-10 13:17 UTCEPSS rescoreEPSS 90% · 99th percentile
  23. 2026-06-07 15:21 UTCEPSS rescoreEPSS 90% · 99th percentile
  24. 2026-06-05 22:43 UTCEPSS rescoreEPSS 90% · 99th percentile
  25. 2026-06-05 06:07 UTCEPSS rescoreEPSS 90% · 99th percentile
  26. 2026-06-04 13:09 UTCEPSS rescoreEPSS 90% · 99th percentile
  27. 2026-06-02 20:10 UTCEPSS rescoreEPSS 90% · 99th percentile
  28. 2026-05-31 07:27 UTCEG score recompute
  29. 2026-05-31 07:27 UTCVendor advisory
  30. 2026-05-31 07:27 UTCGHSA enrichmentGHSA-47q7-qpgp-938j · GitHub severity HIGH
  31. 2026-05-29 13:40 UTCEPSS rescoreEPSS 90% · 99th percentile
  32. 2026-05-27 13:37 UTCEPSS rescoreEPSS 90% · 99th percentile
  33. 2026-05-24 16:42 UTCOSV refresh
  34. 2026-05-20 11:20 UTCEPSS rescoreEPSS 90% · 99th percentile
  35. 2026-05-18 21:29 UTCEPSS rescoreEPSS 90% · 99th percentile

Publicly available exploits

(6 references)

Public exploit code is referenced for this CVE (1 Metasploit module, 4 Exploit-DB entries, 1 GitHub PoC). Defenders should treat patch urgency accordingly.

  • Exploit-DBEDB-16752✓ verified
    Published Feb 15, 2010

    Apache mod_rewrite - LDAP protocol Buffer Overflow (Metasploit)

    Open source ↗
  • Metasploitexploit/windows/http/apache_mod_rewrite_ldap✓ verified
    Published Mar 10, 2009

    Apache Module mod_rewrite LDAP Protocol Buffer Overflow

    Open source ↗
  • Exploit-DBEDB-3996✓ verified
    Published May 26, 2007

    Apache 2.0.58 mod_rewrite (Windows 2003) - Remote Overflow

    Open source ↗
  • Exploit-DBEDB-3680✓ verified
    Published Apr 7, 2007

    Apache mod_rewrite (Windows x86) - Off-by-One Remote Overflow

    Open source ↗
  • Exploit-DBEDB-2237✓ verified
    Published Aug 21, 2006

    Apache < 1.3.37/2.0.59/2.2.3 mod_rewrite - Remote Overflow

    Open source ↗
  • GitHub PoCdefensahacker/CVE-2006-3747
    Published Nov 26, 2016

    Information about my advisory on CVE-2006-3747 (Apache mod_rewrite LDAP off-by-one buffer overflow).. At the time, it was the first public working exploit :)

    Open source ↗

Frequently asked(4)

What is CVE-2006-3747?
CVE-2006-3747 is a high-severity vulnerability; its CVE record was published on July 28, 2006. Off-by-one error in the ldap scheme handling in the Rewrite module (mod_rewrite) in Apache 1.3 from 1.3.28, 2.0.46 and other versions before 2.0.59, and 2.2, when RewriteEngine is enabled, allows remote attackers to cause a denial of service (application crash) and possibly execute arbitrary code…
When was CVE-2006-3747 made public?
CVE-2006-3747 was made public on July 27, 2006: that is the date its CVE record's CNA, Red Hat, Inc., gives for when the vulnerability was made public. The CVE record itself was published on July 28, 2006. EchelonGraph's copy of the record carries a last-modified date of April 16, 2026; the record at its source may have been updated since.
Is CVE-2006-3747 actively exploited?
CVE-2006-3747 is not currently on CISA's Known Exploited Vulnerabilities catalog. EchelonGraph's EG-KEV model places it in Tier 2 (Weaponized), which is not evidence of exploitation: a Metasploit module exists for it, and Exploit-DB marks a public exploit for it as verified. EchelonGraph does not test whether exploit code works. FIRST EPSS estimates a 97% probability of exploitation in the next 30 days (99th percentile of EPSS-scored CVEs).
How do I remediate CVE-2006-3747?
A fix for CVE-2006-3747 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

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