Security Resilience

CVE-2023-4001

Auth Bypass in Fedoraproject Fedora 38 … 39

Published
15 January 2024
Modified
21 November 2024
Patch / advisory
CVSS Score v3.1 6.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0054 44th percentile
Risk Priority 51 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-2023-4001 is a medium-severity Authentication Bypass by Spoofing (CWE-290) vulnerability in Fedoraproject Fedora. Its CVSS base score is 6.8 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Junk Data (T1001.001); ranked at the 44th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to IA-2 (Identification and Authentication (Organizational Users)) and IA-3 (Device Identification and Authentication) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

An authentication bypass flaw was found in GRUB due to the way that GRUB uses the UUID of a device to search for the configuration file that contains the password hash for the GRUB password protection feature. An attacker capable…

more

of attaching an external drive such as a USB stick containing a file system with a duplicate UUID (the same as in the "/boot/" file system) can bypass the GRUB password protection feature on UEFI systems, which enumerate removable drives before non-removable ones. This issue was introduced in a downstream patch in Red Hat's version of grub2 and does not affect the upstream package.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1001.001 Junk Data Command And Control
Adversaries may add junk data to protocols used for command and control to make detection more difficult.
T1003.003 NTDS Credential Access
Adversaries may attempt to access or create a copy of the Active Directory domain database in order to steal credential information, as well as obtain other information about domain members such as devices, users, and access rights.
T1003.005 Cached Domain Credentials Credential Access
Adversaries may attempt to access cached domain credentials used to allow authentication to occur in the event a domain controller is unavailable.
T1006 Direct Volume Access Stealth
Adversaries may directly access a volume to bypass file access controls and file system monitoring.
T1021.003 Distributed Component Object Model Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
T1027 Obfuscated Files or Information Stealth
Adversaries may attempt to make an executable or file difficult to discover or analyze by encrypting, encoding, or otherwise obfuscating its contents on the system or in transit.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-1048Same product: Fedoraproject Fedora
CVE-2024-3843Same product: Fedoraproject Fedora
CVE-2024-34397Same product: Fedoraproject Fedora
CVE-2026-7507Same vendor: Redhat
CVE-2024-0553Same product: Fedoraproject Fedora
CVE-2024-5037Same vendor: Redhat
CVE-2023-4156Same product: Fedoraproject Fedora
CVE-2023-42843Same product: Fedoraproject Fedora
CVE-2023-4692Same product: Gnu Grub2
CVE-2023-4693Same product: Gnu Grub2

Affected Assets

gnu
grub2
all versions
redhat
enterprise linux
9.0
fedoraproject
fedora
38, 39

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 3 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V6.4.3
  • V10.4.16
  • V11.4.3

Mitigating Controls (NIST 800-53 r5) AI

Proper unique identification and authentication of users directly stops spoofing-based bypass of authentication.

Device identification and authentication before connection prevents spoofing of devices to bypass auth.

Authentication of non-organizational users blocks external spoofing attempts against the scheme.

Authenticator management ensures credentials cannot be easily spoofed or reused to bypass authentication.

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.

PR.AA-02 partial match
blocks

Proofing and binding identities reduces spoofing opportunities during enrollment but does not address runtime authentication implementation flaws.

PR.AA-03 partial match
blocks

Requiring authentication of users/services/hardware directly counters spoofing-based bypass when strong methods are used.

PR.AA-04 partial match
blocks

Protecting, conveying, and verifying identity assertions specifically prevents the spoofing that enables authentication bypass.

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
blocks

A.5.15 only requires that an access control policy and requirements be defined and communicated; it does not itself implement, enforce or configure any authentication scheme that would stop spoofing attacks from bypassing authentication, so the weakness remains fully exploitable.

blocks

A.5.16 manages the lifecycle, uniqueness, and accountability of identities; it does not implement or strengthen authentication schemes against spoofing, so the CWE-290 exploit remains possible even when identities are correctly provisioned and tracked.

blocks

Authentication information management directly addresses credential handling that prevents spoofing.

blocks

A.5.18 governs the provisioning, review, and revocation of already-granted access rights to authenticated identities; it has no bearing on whether an authentication scheme can be spoofed or bypassed before any rights are assigned.

removes

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (higher-evidence rows only; rows rated `none` are excluded).

Oracle Linux 8 (1 rule)
  • V-248827 OL 8 must not have the rsh-server package installed. blocks CWE-290
RHEL 7 (1 rule)
  • V-204442 The Red Hat Enterprise Linux operating system must not have the rsh-server package installed. blocks CWE-290
RHEL 8 (1 rule)
  • V-230492 RHEL 8 must not have the rsh-server package installed. blocks CWE-290

References