ssh-agent in OpenSSH before 8.5 has a double free that may be relevant in a few less-common scenarios, such as unconstrained agent-socket access on a legacy operating system, or the forwarding of an agent to an attacker-controlled host.
Weakness
The product calls free() twice on the same memory address.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Openssh | Openbsd | 8.2 (including) | 8.5 (excluding) |
| Openssh | Ubuntu | devel | * |
| Openssh | Ubuntu | esm-infra/focal | * |
| Openssh | Ubuntu | focal | * |
| Openssh | Ubuntu | groovy | * |
| Openssh | Ubuntu | trusty | * |
| Openssh-ssh1 | Ubuntu | upstream | * |
Potential Mitigations
References
- https://github.com/openssh/openssh-portable/commit/e04fd6dde16de1cdc5a4d9946397ff60d96568db
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KQWGII3LQR4AOTPPFXGMTYE7UDEWIUKI/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TXST2CML2MWY3PNVUXX7FFJE3ATJMNVZ/
- https://security.gentoo.org/glsa/202105-35
- https://security.netapp.com/advisory/ntap-20210416-0002/
- https://www.openssh.com/security.html
- https://www.openssh.com/txt/release-8.5
- https://www.openwall.com/lists/oss-security/2021/03/03/1
- https://www.oracle.com//security-alerts/cpujul2021.html
- https://github.com/openssh/openssh-portable/commit/e04fd6dde16de1cdc5a4d9946397ff60d96568db
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KQWGII3LQR4AOTPPFXGMTYE7UDEWIUKI/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TXST2CML2MWY3PNVUXX7FFJE3ATJMNVZ/
- https://security.gentoo.org/glsa/202105-35
- https://security.netapp.com/advisory/ntap-20210416-0002/
- https://www.openssh.com/security.html
- https://www.openssh.com/txt/release-8.5
- https://www.openwall.com/lists/oss-security/2021/03/03/1
- https://www.oracle.com//security-alerts/cpujul2021.html