HOMEVULNERABILITIESCVE-2009-3727
MEDIUM

CVE-2009-3727

CWE-200Published: November 10, 2009· Updated: Jun 16, 2026

5.0
CVSS v3.1

Official Description

Asterisk Open Source 1.2.x before 1.2.35, 1.4.x before 1.4.26.3, 1.6.0.x before 1.6.0.17, and 1.6.1.x before 1.6.1.9; Business Edition A.x.x, B.x.x before B.2.5.12, C.2.x.x before C.2.4.5, and C.3.x.x before C.3.2.2; AsteriskNOW 1.5; and s800i 1.3.x before 1.3.0.5 generate different error messages depending on whether a SIP username is valid, which allows remote attackers to enumerate valid usernames via multiple crafted REGISTER messages with inconsistent usernames in the URI in the To header and the Digest in the Authorization header.

NVD Source

Technical Analysis

CVE-2009-3727 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

From a weakness classification perspective (CWE-200): Information exposure vulnerabilities leak sensitive data to unauthorized actors.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.
User Interaction
Scope
Impact
ConfidentialityP
IntegrityNone
AvailabilityNone
AV:N/AC:L/Au:N/C:P/I:N/A:N

Affected Vendors & Products

digium3 product(s)
asteriskasterisknows800i
Source: NVD CPE · 133 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttp://www.securityfocus.com/bid/36924
PATCHhttp://www.securityfocus.com/bid/36924
ADVISORYhttp://downloads.asterisk.org/pub/security/AST-2009-008.html
ADVISORYhttp://secunia.com/advisories/37265
ADVISORYhttp://downloads.asterisk.org/pub/security/AST-2009-008.html
ADVISORYhttp://secunia.com/advisories/37265

All References (24)

→
http://downloads.asterisk.org/pub/security/AST-2009-008.htmlVendor Advisory
→
http://osvdb.org/59697
→
http://secunia.com/advisories/37265Vendor Advisory
→
http://secunia.com/advisories/37479
→
http://secunia.com/advisories/37677
→
http://www.debian.org/security/2009/dsa-1952
→
http://www.securityfocus.com/bid/36924Patch
→
http://www.securitytracker.com/id?1023133
→
https://bugzilla.redhat.com/show_bug.cgi?id=523277
→
https://bugzilla.redhat.com/show_bug.cgi?id=533137
→
https://www.redhat.com/archives/fedora-package-announce/2009-November/msg00789.html
→
https://www.redhat.com/archives/fedora-package-announce/2009-November/msg00838.html
→
http://downloads.asterisk.org/pub/security/AST-2009-008.htmlVendor Advisory
→
http://osvdb.org/59697
→
http://secunia.com/advisories/37265Vendor Advisory

Quick Facts

CVE IDCVE-2009-3727
CVSS Score5.0 / 10
SeverityMEDIUM
WeaknessCWE-200
CISA KEVNo
Affected1 vendor(s)
PublishedNov 10, 2009

Related CVEs (CWE-200)

CVE-2015-0987
10.0
CVE-2017-2320
10.0
CVE-2026-27604
10.0
CVE-2025-22612
10.0
CVE-2008-1155
10.0
CVE-2020-13702
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2009-3727 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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