A missing allocation check in sftp server processing read requests may cause a NULL dereference on low-memory conditions. The malicious client can request up to 4GB SFTP reads, causing allocation of up to 4GB buffers, which was not being checked for failure. This will likely crash the authenticated users sftp server connection (if implemented as forking as recommended). For thread-based servers, this might also cause DoS for legitimate users.
Given this code is not in any released versions, no security releases have been issued.
A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Libssh | Libssh | * | 0.8.9 (excluding) |
| Libssh | Ubuntu | bionic | * |
| Libssh | Ubuntu | trusty | * |
| Libssh | Ubuntu | xenial | * |