Severity: moderate
CVSS 3.1: 6.5 (medium) CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Affected versions:
- Apache MINA SSHD 1.0.0 before 2.20.0
- Apache MINA SSHD 3.0.0-M1 before 3.0.0-M6
Description:
Server-side memory exhaustion in Apache MINA SSHD 1.0.0 to 2.19.0 and 3.0.0-M1
to 3.0.0-M5, component sshd-sftp, in the SFTP v6
check-file-name/check-file-handle extension. Apache MINA SSHD is a Java library
for client-side and server-side SSH.
Using a very small "block size" (for instance 256, which is the minimum) on a
huge file generates many (file size / block size) hashes. The resulting SFTP
reply message was accumulated fully in memory server-side, which could, with a
suitably large (possibly sparse) file exhaust the server-side memory, taking
down the server.
Users are recommended to upgrade to version 2.20.0 or 3.0.0-M6, which fix this
issue by imposing a maximum limit on the size of the reply. Many SFTP
implementations have a general limit on the size of SFTP messages anyway;
typically 256kB as in OpenSSH or also in Apache MINA SSHD.
Credit:
Ho1aAs <[email protected]> (finder)
References:
https://mina.apache.org/
https://www.cve.org/CVERecord?id=CVE-2026-94029
