In the Linux kernel, the following vulnerability has been resolved: NFSD: Fix READDIR buffer overflow If a client sends a READDIR count argument that is too small (say, zero), then the buffer size calculation in the new init_dirlist helper functions results in an underflow, allowing the XDR stream functions to write beyond the actual buffer. This calculation has always been suspect. NFSD has never sanity- checked the READDIR count argument, but the old entry encoders managed the problem correctly. With the commits below, entry encoding changed, exposing the underflow to the pointer arithmetic in xdr_reserve_space(). Modern NFS clients attempt to retrieve as much data as possible for each READDIR request. Also, we have no unit tests that exercise the behavior of READDIR at the lower bound of @count values. Thus this case was missed during testing.
History

Mon, 04 Nov 2024 13:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2024-03-04T18:15:38.706Z

Updated: 2024-11-04T11:59:32.598Z

Reserved: 2024-03-04T18:12:48.835Z

Link: CVE-2021-47107

cve-icon Vulnrichment

Updated: 2024-08-04T05:24:39.886Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2024-03-04T19:15:18.793

Modified: 2024-11-21T06:35:24.743

Link: CVE-2021-47107

cve-icon Redhat

Severity : Moderate

Publid Date: 2024-03-04T00:00:00Z

Links: CVE-2021-47107 - Bugzilla