sshd in OpenSSH before 7.4 allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via an out-of-sequence NEWKEYS message, as demonstrated by Honggfuzz, related to kex.c and packet.c.
Weakness
The product dereferences a pointer that it expects to be valid but is NULL.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Openssh | Openbsd | * | 7.4 (excluding) |
| Red Hat Enterprise Linux 7 | RedHat | openssh-0:7.4p1-11.el7 | * |
| Openssh | Ubuntu | esm-infra-legacy/trusty | * |
| Openssh | Ubuntu | esm-infra/xenial | * |
| Openssh | Ubuntu | precise/esm | * |
| Openssh | Ubuntu | trusty | * |
| Openssh | Ubuntu | trusty/esm | * |
| Openssh | Ubuntu | upstream | * |
| Openssh | Ubuntu | xenial | * |
Potential Mitigations
References
- http://blog.swiecki.net/2018/01/fuzzing-tcp-servers.html
- http://www.securityfocus.com/bid/102780
- https://anongit.mindrot.org/openssh.git/commit/?id=28652bca29046f62c7045e933e6b931de1d16737
- https://cert-portal.siemens.com/productcert/pdf/ssa-676336.pdf
- https://kc.mcafee.com/corporate/index?page=content\u0026id=SB10284
- https://lists.debian.org/debian-lts-announce/2018/01/msg00031.html
- https://lists.debian.org/debian-lts-announce/2018/09/msg00010.html
- https://security.netapp.com/advisory/ntap-20180423-0003/
- https://support.f5.com/csp/article/K32485746?utm_source=f5support\u0026amp%3Butm_medium=RSS
- https://usn.ubuntu.com/3809-1/
- https://www.openssh.com/releasenotes.html
- http://blog.swiecki.net/2018/01/fuzzing-tcp-servers.html
- http://www.securityfocus.com/bid/102780
- https://anongit.mindrot.org/openssh.git/commit/?id=28652bca29046f62c7045e933e6b931de1d16737
- https://cert-portal.siemens.com/productcert/pdf/ssa-676336.pdf
- https://kc.mcafee.com/corporate/index?page=content\u0026id=SB10284
- https://lists.debian.org/debian-lts-announce/2018/01/msg00031.html
- https://lists.debian.org/debian-lts-announce/2018/09/msg00010.html
- https://security.netapp.com/advisory/ntap-20180423-0003/
- https://support.f5.com/csp/article/K32485746?utm_source=f5support\u0026amp%3Butm_medium=RSS
- https://usn.ubuntu.com/3809-1/
- https://www.openssh.com/releasenotes.html