A flaw exists in the nbdkit "blocksize" filter that can be triggered by a specific type of client request. When a client requests block status information for a very large data range, exceeding a certain limit, it causes an internal error in the nbdkit, leading to a denial of service.

A flaw exists in the nbdkit "blocksize" filter that can be triggered by a specific type of client request. When a client requests block status information for a very large data range, exceeding a certain limit, it causes an internal error in the nbdkit, leading to a denial of service.

Affected: openEuler:22.03-LTS-SP3: nbdkit

NBD (Network Block Device) is a protocol for accessing Block Devices (hard disks and disk-like things) over a Network. nbdkit is a toolkit for creating NBD servers. The key features are: * Multithreaded NBD server written in C with good performance. * Minimal dependencies for the basic server. * Liberal license (BSD) allows nbdkit to be linked to proprietary libraries or included in proprietary code. * Well-documented, simple plugin API with a stable ABI guarantee. Lets you export “unconventional” block devices easily. * You can write plugins in C, Lua, Perl, Python, OCaml, Ruby, Rust, shell script or Tcl. * Filters can be stacked in front of plugins to transform the output. Security Fix(es):

There's a flaw in the nbdkit server when handling responses from its plugins regarding the status of data blocks. If a client makes a specific request for a very large data range, and a plugin responds with an even larger single block, the nbdkit server can encounter a critical internal error, leading to a denial-of-service.(CVE-2025-47711)

A flaw exists in the nbdkit "blocksize" filter that can be triggered by a specific type of client request. When a client requests block status information for a very large data range, exceeding a certain limit, it causes an internal error in the nbdkit, leading to a denial of service.(CVE-2025-47712)

nbdkit-1.42.3-1.1 on GA media

Security update for nbdkit

Affected: Ubuntu:16.04:LTS: nbdkit, Ubuntu:20.04:LTS: nbdkit, Ubuntu:22.04:LTS: nbdkit, Ubuntu:24.04:LTS: nbdkit, Ubuntu:25.10: nbdkit, Ubuntu:26.04:LTS: nbdkit

A flaw exists in the nbdkit "blocksize" filter that can be triggered by a specific type of client request. When a client requests block status information for a very large data range, exceeding a certain limit, it causes an internal error in the nbdkit, leading to a denial of service.