7.5

CVE-2023-28857: apereo cas

CVSS: 7.5v3.1HighModified
AliasesGHSA-p78h-m8pv-g9gm
Published 27-06-2023Last modified 27-11-2024
Open JSON

Vulnerability summary

CVE-2023-28857 is a high (CVSS 7.5) vulnerability in apereo cas. EPSS estimates a 0.50% chance of exploitation in the next 30 days, higher than 41.7% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (NVD)
EPSS score
0.50%
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. 27-06-2023
    PublishedVulnerability first disclosed.
  2. 27-11-2024
    Last modifiedVulnerability information updated.

Description

Apereo CAS is an open source multilingual single sign-on solution for the web. Apereo CAS can be configured to use authentication based on client X509 certificates. These certificates can be provided via TLS handshake or a special HTTP header, such as “ssl_client_cert”. When checking the validity of the provided client certificate, X509CredentialsAuthenticationHandler performs check that this certificate is not revoked. To do so, it fetches URLs provided in the “CRL Distribution Points” extension of the certificate, which are taken from the certificate itself and therefore can be controlled by a malicious user. If the CAS server is configured to use an LDAP server for x509 authentication with a password, for example by setting a “cas.authn.x509.ldap.ldap-url” and “cas.authn.x509.ldap.bind-credential” properties, X509CredentialsAuthenticationHandler fetches revocation URLs from the certificate, which can be LDAP urls. When making requests to this LDAP urls, Apereo CAS uses the same password as for initially configured LDAP server, which can lead to a password leak. An unauthenticated user can leak the password used to LDAP connection configured on server. This issue has been addressed in version 6.6.6. Users are advised to upgrade. There are no known workarounds for this vulnerability.

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

0.50%

Chance of exploitation in the next 30 days

Percentile

42%

Versus all other CVEs

30-day change

0.00 pp

From 0.50% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.50%

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

Apereo2 products
Org.apereo.cas1 product
  • cas-server-support-x509-core≥ 6.5.0, < 6.6.6

2 vendors · 3 products

References

9 links