4.8

CVE-2023-39953: nextcloud security-advisories

CVSS: 4.8v3.1MediumModified
Published 10-08-2023Last modified 03-10-2024

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.

Overall risk
19/100
0100
Low · default modelHow is this calculated?
CVSS score
4.8/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.54%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 10-08-2023
    PublishedVulnerability first disclosed.
  2. 03-10-2024
    Last 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

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

19-09-202619-10-2026
EPSS score
0.54%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Nextcloud2 products

1 vendor · 2 products

References

3 links