Asterisk IAX2 Protocol ACK response denial of service
| asterisk-iax2protocol-ack-dos (41966) |  Low Risk |
Description:
Asterisk is vulnerable to a denial of service, caused by the failure to verify the ACK response has a call number matching the server's reply to a NEW message during IAX2 handshakes by the IAX2 Protocol. By sending a spoofed ACK response message, a remote attacker could cause the system to release early audio packets to the targeted address and cause a denial of service.
*CVSS:
| Base Score: | 5 |
| Access Vector: | Network |
| Access Complexity: | Low |
| Authentication: | None |
| Confidentiality Impact: | None |
| Integrity Impact: | None |
| Availability Impact: | Partial |
| Temporal Score: | 3.7 |
| Exploitability: | Unproven |
| Remediation Level: | Official-Fix |
| Report Confidence: | Confirmed |
Consequences:
Denial of Service
Remedy:
Refer to AST-2008-006 for patch, upgrade or suggested workaround information. See References.
References:
- AltSci Concepts Web site: AltSci Concepts IAX2 Exploit Framework.
- AST-2008-006: 3-way handshake in IAX2 incomplete.
- Digium Issue Tracker ID 0010078: IAX2 protocol flaw in IC_NEW could cause reflective amplification DoS.
- BID-28901: Asterisk IAX2 Packet Amplification Remote Denial of Service Vulnerability
- CVE-2008-1897: The IAX2 channel driver (chan_iax2) in Asterisk Open Source 1.0.x, 1.2.x before 1.2.28, and 1.4.x before 1.4.19.1; Business Edition A.x.x, B.x.x before B.2.5.2, and C.x.x before C.1.8.1; AsteriskNOW before 1.0.3; Appliance Developer Kit 0.x.x; and s800i before 1.1.0.3, when configured to allow unauthenticated calls, does not verify that an ACK response contains a call number matching the server's reply to a NEW message, which allows remote attackers to cause a denial of service (traffic amplification) via a spoofed ACK response that does not complete a 3-way handshake. NOTE: this issue exists because of an incomplete fix for CVE-2008-1923.
- DSA-1563: asterisk -- denial of service
- GLSA-200905-01: Asterisk: Multiple vulnerabilities
- SA29927: Asterisk IAX2 Handshake Denial of Service
- SECTRACK ID: 1019918: Asterisk IAX2 Protocol Verification Bug Lets Remote Users Deny Service
- VUPEN/ADV-2008-1324: Asterisk IAX2 Protocol Verification Remote Denial of Service Vulnerability
Platforms Affected:
- Debian Debian Linux 4.0
- Digium Asterisk Business Edition B.2.5.1
- Digium Asterisk Business Edition C.1.8
- Digium Asterisk Open Source 1.2.27
- Digium Asterisk Open Source 1.4.19
- Digium AsteriskNOW 1.0.2
- Digium s800i 1.1.0.2
- Gentoo Linux
Reported:
Apr 22, 2008
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The information within this database may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. In no event shall IBM be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information.