CVE-2022-50861

A flaw was identified in the Linux kernel’s NFSD NFSv2 GETACL result encoder. During conversion to xdr_stream, leftover code erroneously set the page_len field of the send buffer. The XDR stream encoders are expected to manage buffer length automatically, and the incorrect manual setting can result in additional unused data beyond the legitimate response message being transmitted. Although most NFSv2 clients will ignore this extra data, it may contain stale kernel memory contents and can be observed on the network

This vulnerability is rated as Moderate severity rather than Low because uninitialized kernel memory contents are exposed over the network, though risk is bounded since the issue is restricted to the legacy NFSv2 protocol and does not permit code execution or state alteration. On Red Hat Enterprise Linux, the kernel NFS server is not enabled by default, and NFSv2 is disabled by default in standard server configurations. Systems are only susceptible if they are explicitly configured to run an NFS server with support for legacy NFSv2 clients enabled.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.