Security Resilience

CVE-2023-20900

Auth Bypass in Fedoraproject Fedora 37 … 39

Published
31 August 2023
Modified
08 October 2026
Patch / advisory
CVSS Score v3.1 7.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.015 73th percentile
Risk Priority 55 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2023-20900 is a high-severity Authentication Bypass by Capture-replay (CWE-294) vulnerability in Fedoraproject Fedora. Its CVSS base score is 7.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Protocol or Service Impersonation (T1001.003); ranked in the top 27% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A malicious actor that has been granted Guest Operation Privileges https://docs.vmware.com/en/VMware-vSphere/8.0/vsphere-security/GUID-6A952214-0E5E-4CCF-9D2A-90948FF643EC.html  in a target virtual machine may be able to elevate their privileges if that target virtual machine has been assigned a more privileged Guest Alias https://vdc-download.vmware.com/vmwb-repository/dcr-public/d1902b0e-d479-46bf-8ac9-cee0e31e8ec0/07ce8dbd-db48-4261-9b8f-c6d3ad8ba472/vim.vm.guest.AliasManager.html .

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1001.003 Protocol or Service Impersonation Command And Control
Adversaries may impersonate legitimate protocols or web service traffic to disguise command and control activity and thwart analysis efforts.
T1003.007 Proc Filesystem Credential Access
Adversaries may gather credentials from the proc filesystem or `/proc`.
T1003.008 /etc/passwd and /etc/shadow Credential Access
Adversaries may attempt to dump the contents of <code>/etc/passwd</code> and <code>/etc/shadow</code> to enable offline password cracking.
T1006 Direct Volume Access Stealth
Adversaries may directly access a volume to bypass file access controls and file system monitoring.
T1007 System Service Discovery Discovery
Adversaries may try to gather information about registered local system services.
T1010 Application Window Discovery Discovery
Adversaries may attempt to get a listing of open application windows.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-31084Same product: Debian Debian Linux
CVE-2023-38403Same product: Debian Debian Linux
CVE-2023-35001Same product: Debian Debian Linux
CVE-2023-4004Same product: Debian Debian Linux
CVE-2023-2269Same product: Debian Debian Linux
CVE-2023-3338Same product: Debian Debian Linux
CVE-2023-3141Same product: Debian Debian Linux
CVE-2023-23559Same product: Debian Debian Linux
CVE-2023-4273Same product: Debian Debian Linux
CVE-2024-34397Same product: Debian Debian Linux

Affected Assets

vmware
tools
10.3.0 — 12.3.0 · 10.3.0 — 10.3.26
vmware
open vm tools
10.3.0 — 12.3.0
fedoraproject
fedora
37, 38, 39
debian
debian linux
10.0, 11.0, 12.0
netapp
ontap select deploy administration utility
all versions

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V10.4.16
  • V10.5.1

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-294

Allows detection of capture-replay attacks by showing the replayed logon's timestamp as the last logon.

addresses: CWE-294

Protects against replay of captured session tokens or credentials by requiring authenticated, fresh session channels.

addresses: CWE-294

Wireless link protections commonly incorporate replay protection, reducing the exploitability of capture-replay weaknesses.

addresses: CWE-294

Accurate synchronized time enables tight timestamp windows that directly limit capture-replay windows in authentication protocols.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

DE.CM-01 partial match
blocks

Network monitoring may detect anomalous replays after the fact but does not prevent the design flaw.

PR.AA-03 partial match
blocks

Strong authentication methods can reduce replay risk but do not inherently address captured messages.

PR.AA-04 partial match
blocks

Protecting and verifying identity assertions prevents replay of captured authentication material.

PR.DS-02 partial match
blocks

Encryption and integrity protections for data-in-transit directly block capture-replay of credentials or tokens.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

removes
removes
removes
removes
removes

References