Asterisk is an open source private branch exchange and telephony toolkit. Prior to versions 18.26.4 and 18.9-cert17, RTP UDP ports and internal resources can leak due to a lack of session termination. This could result in leaks and resource exhaustion. This issue has been patched in versions 18.26.4 and 18.9-cert17.
The product does not properly control the allocation and maintenance of a limited resource.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Asterisk | Sangoma | * | 18.26.4 (excluding) |
| Certified_asterisk | Sangoma | * | 18.9 (excluding) |
| Certified_asterisk | Sangoma | 18.9-cert1 (including) | 18.9-cert1 (including) |
| Certified_asterisk | Sangoma | 18.9-cert1-rc1 (including) | 18.9-cert1-rc1 (including) |
| Certified_asterisk | Sangoma | 18.9-cert10 (including) | 18.9-cert10 (including) |
| Certified_asterisk | Sangoma | 18.9-cert11 (including) | 18.9-cert11 (including) |
| Certified_asterisk | Sangoma | 18.9-cert12 (including) | 18.9-cert12 (including) |
| Certified_asterisk | Sangoma | 18.9-cert13 (including) | 18.9-cert13 (including) |
| Certified_asterisk | Sangoma | 18.9-cert14 (including) | 18.9-cert14 (including) |
| Certified_asterisk | Sangoma | 18.9-cert15 (including) | 18.9-cert15 (including) |
| Certified_asterisk | Sangoma | 18.9-cert16 (including) | 18.9-cert16 (including) |
| Certified_asterisk | Sangoma | 18.9-cert2 (including) | 18.9-cert2 (including) |
| Certified_asterisk | Sangoma | 18.9-cert3 (including) | 18.9-cert3 (including) |
| Certified_asterisk | Sangoma | 18.9-cert4 (including) | 18.9-cert4 (including) |
| Certified_asterisk | Sangoma | 18.9-cert5 (including) | 18.9-cert5 (including) |
| Certified_asterisk | Sangoma | 18.9-cert6 (including) | 18.9-cert6 (including) |
| Certified_asterisk | Sangoma | 18.9-cert7 (including) | 18.9-cert7 (including) |
| Certified_asterisk | Sangoma | 18.9-cert8 (including) | 18.9-cert8 (including) |
| Certified_asterisk | Sangoma | 18.9-cert8-rc1 (including) | 18.9-cert8-rc1 (including) |
| Certified_asterisk | Sangoma | 18.9-cert8-rc2 (including) | 18.9-cert8-rc2 (including) |
| Certified_asterisk | Sangoma | 18.9-cert9 (including) | 18.9-cert9 (including) |
| Asterisk | Ubuntu | upstream | * |
Mitigation of resource exhaustion attacks requires that the target system either:
The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.