CVE-2023-39953: nextcloud security-advisories
Vulnerability summary
CVE-2023-39953 is a medium (CVSS 4.8) vulnerability in nextcloud security-advisories. EPSS estimates a 0.54% chance of exploitation in the next 30 days, higher than 44.4% of scored vulnerabilities.
Timeline
- 10-08-2023PublishedVulnerability first disclosed.
- 03-10-2024Last modifiedVulnerability information updated.
Description
user_oidc provides the OIDC connect user backend for Nextcloud, an open-source cloud platform. Starting in version 1.0.0 and prior to version 1.3.3, missing verification of the issuer would have allowed an attacker to perform a man-in-the-middle attack returning corrupted or known token they also have access to. user_oidc 1.3.3 contains a patch. No known workarounds are available.
CVSS metrics
2 scores · 2 sources · 1 version- NVDNIST4.8MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
EPSS trend
Probability
0.54%
Chance of exploitation in the next 30 days
Percentile
44%
Versus all other CVEs
30-day change
0.00 pp
From 0.54% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Nextcloud2 products
- security-advisories≥ 1.0.0, < 1.3.3
- user_oidc≥ 1.0.0, < 1.3.3
1 vendor · 2 products
References
3 links- github.com/nextcloud/security-advisories/security/advisories/GHSA-xx3h-v363-q36jX Refsource CONFIRMPatchVendor Advisory