CVE-2023-28857Public exploitNetwork attack vector

Unauthenticated LDAP password disclosure via CRL URL

Published Jun 27, 2023 · Updated Nov 27, 2024

Credential exposure in Apereo CAS 6.5.0 through 6.5.9 and 6.6.0 through 6.6.5 allows remote attackers to obtain an LDAP password. X509CredentialsAuthenticationHandler follows attacker-controlled LDAP CRL distribution URLs and reuses the configured directory bind credentials on those outbound requests. The CAS REST API, X.509 authentication, LDAP-backed revocation checking, and a bind password must all be configured; reverse-proxy certificate validation raises the gate to a signed malicious certificate.

CVSS severity6.3
Medium
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Credential exposure in Apereo CAS 6.5.0 through 6.5.9 and 6.6.0 through 6.6.5 allows remote attackers to obtain an LDAP password. X509CredentialsAuthenticationHandler follows attacker-controlled LDAP CRL distribution URLs and reuses the configured directory bind credentials on those outbound requests. The CAS REST API, X.509 authentication, LDAP-backed revocation checking, and a bind password must all be configured; reverse-proxy certificate validation raises the gate to a signed malicious certificate.

The record

CVE
CVE-2023-28857
Published
Jun 27, 2023
Updated
Nov 27, 2024
Vendor
Apereo
Product
Apereo CAS
Classifications
CWE-200, CWE-522, T1187
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 27, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 27, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 6.5.0, < 6.5.9.1
  2. Affected versionversion=>= 6.6.0, < 6.6.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Apereo · Apereo CASversion=>= 6.5.0, < 6.5.9.1; version=>= 6.6.0, < 6.6.6

Published CVSS scores

7.5GitLab Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
6.3GitHub Advisory DatabaseCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N
4.0GitLab Advisory DatabaseCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
CWE-522Insufficiently Protected Credentials
T1187Forced Authentication

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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