CodiMD - Missing Image Access Controls and Unauthorized Image Access

published 2024-07-10 2 y ago modified 2026-06-17 4 mo ago also EUVD-2024-37276

cvss: 5.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.1%; EPSS 1.1% chance of exploitation in 30 days, percentile 67%
public exploits: 0; none known, plus a Nuclei check

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 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.

Patch / fix

fixed in 1

hackmd codimd 2.5.4

CISA SSVC

Exploitation: Proof of concept is public
Automatable: yes
Technical impact: partial
Assessed: 2 y ago (2024-07-11)

Exploit prediction

1.15% chance of exploitation in the next 30 days, higher than 67% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

Nuclei template CodiMD <2.5.4 - Insecure Filename Randomization nuclei detection template
github.com https://github.com/hackmdio/codimd/security/advisories/GHSA-2764-jppc-p2hm referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Affected products

hackmdio codimd
hackmd codimd

Classification

Weakness

CWE-338 Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
CWE-862 Missing Authorization

References

github.com /hackmdio/codimd/security/advisories/GHSA-2764-jppc-p2hm
exploit, mitigation, third-party-advisory

Sources

CVE List CVE-2024-38353
NVD CVE-2024-38353

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary