What’s Vulnerable › Vulnerabilities

CVE-2009-3727

• Severity: medium (CVSS 5.0 v2.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 4.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2009-11-10 · updated 2026-06-16
• Weakness: CWE-200

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.

Affected products

• Digium Asterisk: 1.2.0, 1.2.0-beta1, 1.2.0-beta2, 1.2.0-rc1, 1.2.0-rc2, 1.2.1 (+204)
• Digium Asterisknow: 1.5
• Digium S800I: 1.3.0, 1.3.0.2, 1.3.0.3, 1.3.0.4

References

• http://downloads.asterisk.org/pub/security/AST-2009-008.html
• http://osvdb.org/59697
• http://secunia.com/advisories/37265
• http://secunia.com/advisories/37479
• http://secunia.com/advisories/37677
• http://www.debian.org/security/2009/dsa-1952
• http://www.securityfocus.com/bid/36924
• 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

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