In Dovecot before 2.3.10.1, a crafted SMTP/LMTP message triggers an unauthenticated use-after-free bug in submission-login, submission, or lmtp, and can lead to a crash under circumstances involving many newlines after a command.
Weakness
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Dovecot | Dovecot | * | 2.3.10.1 (excluding) |
| Red Hat Enterprise Linux 8 | RedHat | dovecot-1:2.3.8-4.el8 | * |
| Dovecot | Ubuntu | devel | * |
| Dovecot | Ubuntu | eoan | * |
| Dovecot | Ubuntu | esm-infra/focal | * |
| Dovecot | Ubuntu | focal | * |
| Dovecot | Ubuntu | trusty | * |
Potential Mitigations
References
- http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00059.html
- http://packetstormsecurity.com/files/157771/Open-Xchange-Dovecot-2.3.10-Null-Pointer-Dereference-Denial-Of-Service.html
- http://seclists.org/fulldisclosure/2020/May/37
- http://www.openwall.com/lists/oss-security/2020/05/18/1
- https://dovecot.org/security
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TTZN2VW55ZC2AQBGBJMLRJSZIKSB2NS6/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VVUWHUUAFPC6XGIXYFIPTNBXLHPNM4W6/
- https://usn.ubuntu.com/4361-1/
- https://www.debian.org/security/2020/dsa-4690
- https://www.openwall.com/lists/oss-security/2020/05/18/1
- http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00059.html
- http://packetstormsecurity.com/files/157771/Open-Xchange-Dovecot-2.3.10-Null-Pointer-Dereference-Denial-Of-Service.html
- http://seclists.org/fulldisclosure/2020/May/37
- http://www.openwall.com/lists/oss-security/2020/05/18/1
- https://dovecot.org/security
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TTZN2VW55ZC2AQBGBJMLRJSZIKSB2NS6/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VVUWHUUAFPC6XGIXYFIPTNBXLHPNM4W6/
- https://usn.ubuntu.com/4361-1/
- https://www.debian.org/security/2020/dsa-4690
- https://www.openwall.com/lists/oss-security/2020/05/18/1