7 High
AI Score
Confidence
Low
5 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
NONE
Availability Impact
NONE
AV:N/AC:L/Au:N/C:P/I:N/A:N
0.012 Low
EPSS
Percentile
84.5%
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.
archives.neohapsis.com/archives/bugtraq/2011-12/0151.html
downloads.asterisk.org/pub/security/AST-2011-013.html
lists.digium.com/pipermail/asterisk-dev/2011-November/052191.html
openwall.com/lists/oss-security/2011/12/09/3
openwall.com/lists/oss-security/2011/12/09/4
osvdb.org/77597
secunia.com/advisories/47273
www.debian.org/security/2011/dsa-2367