CVE-2021-47107

Siemens ProductCERT Advisory SSA-265688

criticalEPSS 0.9%

Description

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.

Metrics

Severity
critical
no public PoC known
9.8
Source: nvd-v3
55.9 %
High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
0.9 %
Low — model estimates < 1% exploitation likelihood.
Published
2022-02-18 00:00 UTC

Reanalysis & status changes

Chronological NVD audit events for this CVE — reanalyses, CVSS updates, CPE diffs.

  1. CVE Modified2026-08-04 10:16 UTC· 416baaa9-dc9f-4396-8d5f-8c081fb06d67
    • CVSS V3.1: AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected operating systems

  • linux

    amazon / amazon_linux

  • linux

    suse / basesystem_module15

  • linux

    debian / debian_linux10.0

  • linux

    debian / debian_linux11.0

  • linux

    debian / debian_linux12.0

  • linux

    debian / debian_linux13.0

  • linux

    suse / development_tools_module15

  • linux

    redhat / enterprise_linux10.0

  • linux

    redhat / enterprise_linux8.0

  • linux

    redhat / enterprise_linux9.0

  • linux

    redhat / enterprise_linux_aus8.4

  • linux

    redhat / enterprise_linux_aus8.6

  • linux

    redhat / enterprise_linux_eus10.0

  • linux

    redhat / enterprise_linux_eus8.4

  • linux

    redhat / enterprise_linux_eus9.4

  • linux

    redhat / enterprise_linux_eus9.6

  • linux

    redhat / enterprise_linux_tus8.6

  • linux

    redhat / enterprise_linux_tus8.8

  • linux

    redhat / enterprise_linux_update_services_for_sap_solutions8.6

  • linux

    redhat / enterprise_linux_update_services_for_sap_solutions8.8

  • linux

    redhat / enterprise_linux_update_services_for_sap_solutions9.0

  • linux

    redhat / enterprise_linux_update_services_for_sap_solutions9.2

  • linux

    opensuse / leap15.3

  • linux

    opensuse / leap15.4

Affected products

Products and version ranges extracted from the vendor/CERT advisory. A range like „<4.14.6“ implies the update recommendation „upgrade to 4.14.6 or later“.

  • android

    :linux_kernel::0

  • android

    :linux_kernel:Kernel

  • arista

    cloudvision_agni2024.4.0 – 2025.2.2

  • arista

    cloudvision_portal2024.2.0 – 2026.1.0

  • arista

    velocloud_edge4.5.0 – 6.4.1

  • arista

    velocloud_gateway

  • arista

    velocloud_orchestrator

  • bitnami

    java-min1.9.0

  • Dell

    ECS3.8.1.0

  • Dell

    NetWorkerVirtual Edition

  • Dell

    NetWorkervProxy

  • Dell

    PowerProtect Data Domain7.10.1.70

  • Dell

    PowerProtect Data Domain7.13.1.40

  • Dell

    PowerProtect Data Domain8.3.1.10

  • Dell

    PowerProtect Data Domain8.4.0.0

  • Dell

    PowerProtect Data Domain< 7.10.1.70

    fixed in 7.10.1.70

  • Dell

    PowerProtect Data Domain< 7.13.1.40

    fixed in 7.13.1.40

  • Dell

    PowerProtect Data Domain< 8.3.1.10

    fixed in 8.3.1.10

  • Dell

    PowerProtect Data Domain< 8.4.0.0

    fixed in 8.4.0.0

  • Dell

    PowerScale OneFSNode Firmware Package 14.1

  • Dell

    Secure Connect GatewayAppliance 5.32.00.18

  • Hitachi Energy

    RTU500< 13.9.1

    fixed in 13.9.1

  • HPE

    HP-UXOpenSSL Software <A.03.00.15.001

  • IBM

    AIX7.2

References & sources

Linked CVEs

Show 423 more CVEs
IDCVE-2021-47107
Siemens ProductCERT Advisory SSA-265688 — CVE-2021-47107 | NEOSEC Intel