Security Resilience

CVE-2023-0777

Auth Bypass in Modoboa ≤ 2.0.4

Public PoCAuth Bypass
Published
10 February 2023
Modified
21 November 2024
Patch / advisory
View advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.15 97th percentile
Risk Priority 97 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-2023-0777 is a critical-severity Authentication Bypass by Primary Weakness (CWE-305) vulnerability in Modoboa Modoboa. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Junk Data (T1001.001); ranked in the top 3% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2023-0777 is an authentication bypass vulnerability caused by a primary weakness, affecting the Modoboa mail hosting and management platform in the modoboa/modoboa GitHub repository prior to version 2.0.4. The flaw carries a CVSS 3.1 base score of 9.8 and is associated with CWE-305, indicating that remote attackers can circumvent authentication controls without requiring credentials or user interaction.

Unauthenticated attackers with network access can exploit the weakness to achieve administrative takeover of a Modoboa instance, resulting in full compromise of confidentiality, integrity, and availability of the affected system. Public references, including a PacketStorm entry titled modoboa-2.0.4-Admin-Takeover, document the practical impact of this bypass.

The referenced GitHub commit 47d17ac6643f870719691073956a26e4be0a4806 and the associated huntr.dev bounty entry indicate that the issue was resolved by updating to Modoboa 2.0.4 or later. The EPSS score has reached a current value of 0.7502 with a recorded peak of 0.7615, reflecting sustained exploitation interest after disclosure.

OWASP Top 10 for Web (2025)

A07:2025 Authentication Failures

EU & UK References

Vulnerability Data

Authentication Bypass by Primary Weakness in GitHub repository modoboa/modoboa prior to 2.0.4.

CWE(s)
CWE-305NVD-CWE-Other

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.
attack.mitre.org →
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.
attack.mitre.org →
T1003.006 DCSync Credential Access
Adversaries may attempt to access credentials and other sensitive information by abusing a Windows Domain Controller's application programming interface (API)(Citation: Microsoft DRSR Dec 2017) (Citation: Microsoft GetNCCChanges) (Citati…
attack.mitre.org →
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.
attack.mitre.org →
T1006 Direct Volume Access Stealth
Adversaries may directly access a volume to bypass file access controls and file system monitoring.
attack.mitre.org →
T1007 System Service Discovery Discovery
Adversaries may try to gather information about registered local system services.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-27602Same product: Modoboa Modoboa
CVE-2023-0438Same product: Modoboa Modoboa
CVE-2023-0470Same product: Modoboa Modoboa
CVE-2023-2160Same product: Modoboa Modoboa
CVE-2023-2227Same product: Modoboa Modoboa
CVE-2023-5689Same product: Modoboa Modoboa
CVE-2023-0949Same product: Modoboa Modoboa
CVE-2023-0398Same product: Modoboa Modoboa
CVE-2023-5690Same product: Modoboa Modoboa
CVE-2023-5688Same product: Modoboa Modoboa

Affected Assets

modoboa
modoboa
≤ 2.0.4

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

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

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.

ID.RA-01 partial match
blocks

Identifying and recording vulnerabilities catches the primary weaknesses that allow authentication bypass.

PR.AA-03 partial match
blocks

Strong authentication mechanisms and policy enforcement directly reduce bypass opportunities arising from implementation flaws.

PR.PS-06 partial match
blocks

Secure development practices throughout the SDLC prevent the primary weaknesses that enable 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.

A.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.8.10 Information deletion partial match
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).

Ubuntu 22.04 (1 rule)
  • V-260470 Ubuntu 22.04 LTS, when booted, must require authentication upon booting into single-user and maintenance modes. blocks CWE-305
Ubuntu 24.04 (1 rule)
  • V-270675 Ubuntu 24.04 LTS when booted must require authentication upon booting into single-user and maintenance modes. blocks CWE-305

References