CVE-2011-4597

Severity: medium (CVSS 5.0 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2011-12-15 · updated 2026-06-16
Weakness: CWE-200

Description

The SIP over UDP implementation in Asterisk Open Source 1.4.x before 1.4.43, 1.6.x before 1.6.2.21, and 1.8.x before 1.8.7.2 uses different port numbers for responses to invalid requests depending on whether a SIP username exists, which allows remote attackers to enumerate usernames via a series of requests.

Affected products

Digium Asterisk: 1.8.0, 1.8.0-beta1, 1.8.0-beta2, 1.8.0-beta3, 1.8.0-beta4, 1.8.0-beta5 (+202)

References

http://archives.neohapsis.com/archives/bugtraq/2011-12/0151.html
http://downloads.asterisk.org/pub/security/AST-2011-013.html
http://lists.digium.com/pipermail/asterisk-dev/2011-November/052191.html
http://openwall.com/lists/oss-security/2011/12/09/3
http://openwall.com/lists/oss-security/2011/12/09/4
http://osvdb.org/77597
http://secunia.com/advisories/47273
http://www.debian.org/security/2011/dsa-2367
http://archives.neohapsis.com/archives/bugtraq/2011-12/0151.html
http://downloads.asterisk.org/pub/security/AST-2011-013.html
http://lists.digium.com/pipermail/asterisk-dev/2011-November/052191.html
http://openwall.com/lists/oss-security/2011/12/09/3

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