Cyber Resilience

CVE-2024-38353

Access Control in Hackmd Codimd ≤ 2.5.4

Public PoCAccess Control
Published
10 July 2024
Modified
04 September 2025
Patch / advisory
CVSS Score v3.1 5.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS Score 0.012 64th percentile
Risk Priority 51 floored blend · peak EPSS

Summary

CVE-2024-38353 is a medium-severity PRNG (CWE-338) vulnerability in Hackmd Codimd. Its CVSS base score is 5.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 36% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to AC-24 (Access Control Decisions) and AC-25 (Reference Monitor) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

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

CodiMD before version 2.5.4 contains a missing authentication and access control vulnerability that allows unauthenticated access to uploaded image data. The application does not require valid credentials to retrieve or upload images, and the underlying Formidable library uses insecure random filename generation that increases the chance an attacker can predict image URLs. The issue is tracked under CWE-338 and CWE-862 and carries a CVSS 3.1 score of 5.3.

An unauthenticated attacker who can guess or enumerate an image URL can retrieve the corresponding uploaded content without authorization. Because no authentication check is performed on image endpoints, the same weakness also permits arbitrary image uploads, exposing any previously stored image data once its filename is known.

The vulnerability is resolved in CodiMD 2.5.4, as stated in the GitHub Security Advisory GHSA-2764-jppc-p2hm. The EPSS score remains flat at 0.0532 with no material increase after disclosure.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

CodiMD allows realtime collaborative markdown notes on all platforms. CodiMD before 2.5.4 is missing authentication and access control vulnerability allowing an unauthenticated attacker to gain unauthorised access to image data uploaded to CodiMD. CodiMD does not require valid authentication to…

more

access uploaded images or to upload new image data. An attacker who can determine an uploaded image's URL can gain unauthorised access to uploaded image data. Due to the insecure random filename generation in the underlying Formidable library, an attacker can determine the filenames for previously uploaded images and the likelihood of this issue being exploited is increased. This vulnerability is fixed in 2.5.4.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1606 Forge Web Credentials Credential Access
Adversaries may forge credential materials that can be used to gain access to web applications or Internet services.
T1606.001 Web Cookies Credential Access
Adversaries may forge web cookies that can be used to gain access to web applications or Internet services.
T1548 Abuse Elevation Control Mechanism Privilege Escalation
Adversaries may circumvent mechanisms designed to control privilege elevation to gain higher-level permissions.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-43838Shared CWE-862
CVE-2023-7268Shared CWE-862
CVE-2024-1158Shared CWE-862
CVE-2024-37427Shared CWE-862
CVE-2025-59561Shared CWE-862
CVE-2025-31533Shared CWE-862
CVE-2024-35725Shared CWE-862
CVE-2025-8565Shared CWE-862
CVE-2024-1804Shared CWE-862
CVE-2025-30017Shared CWE-862

Affected Assets

hackmd
codimd
≤ 2.5.4

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 8 hardening rules · 4 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V7.2.3
  • V11.5.1

Mitigating Controls (NIST 800-53 r5) AI

AC-3 directly requires enforcement of authorization decisions on every access request, structurally eliminating missing authorization checks.

Requiring specific approved cryptography for protection directly mandates use of strong PRNGs instead of weak ones.

AC-24 mandates that access control decisions are applied to each request, preventing bypass of authorization logic.

AC-25 requires a tamperproof, always-invoked reference monitor that ensures authorization checks cannot be omitted.

AC-6 reduces the set of actions reachable without proper authorization, limiting blast radius of missing checks.

Engineering principles applied during design and development include selection of cryptographically strong random number generation.

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-05 full match
prevents

Explicitly requires defining, enforcing, and reviewing authorizations and least privilege, directly preventing missing authorization checks.

PR.PS-06 mostly match
prevents

Secure SDLC practices explicitly require cryptographically strong RNG selection and usage in security contexts.

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.

prevents

Mandates use of approved cryptographic controls, directly requiring cryptographically strong RNGs.

finds

Security testing can detect use of weak random number generators.

prevents

Requiring authentication and credentials before any access occurs eliminates the absence of authorization checks that would otherwise allow an unauthenticated actor to reach protected resources.

prevents

Requiring formal authorization of every access request before rights are granted ensures that checks for required permissions are performed, preventing missing authorization checks from being introduced.

prevents

Mandatory authorization checks and central records of granted rights ensure that every access attempt is preceded by an explicit decision rather than relying on missing checks.

mitigates

Segregating the approval of access rights from their implementation provides an independent check that reduces the impact of missing authorization checks in the resulting system configuration.

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` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (3 rules)
  • V-248563 The OL 8 SSH server must be configured to use strong entropy. prevents CWE-338
  • V-248581 OL 8 must require users to provide a password for privilege escalation. prevents CWE-862
  • V-252656 The OL 8 operating system must not be configured to bypass password requirements for privilege escalation. prevents CWE-862
RHEL 7 (2 rules)
  • V-251704 The Red Hat Enterprise Linux operating system must not be configured to bypass password requirements for privilege escalation. prevents CWE-862
  • V-204429 The Red Hat Enterprise Linux operating system must be configured so that users must provide a password for privilege escalation. prevents CWE-862
RHEL 8 (1 rule)
  • V-230253 RHEL 8 must ensure the SSH server uses strong entropy. prevents CWE-338
Ubuntu 22.04 (1 rule)
  • V-260650 Ubuntu 22.04 LTS must implement NIST FIPS-validated cryptography to protect classified information and for the following: To provision digital signatures, to generate cryptographic hashes, and to protect unclassified information requiring confidentiality and cryptographic protection in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. prevents CWE-338

References