CVE-2020-27178
Improper Authentication in Apereo CAS
Apereo CAS 5.3.x before 5.3.16, 6.x before 6.1.7.2, 6.2.x before 6.2.4, and 6.3.x before 6.3.0-RC4 mishandles secret keys with Google Authenticator for multifactor authentication.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
Apereo CAS 5.3.x before 5.3.16, 6.x before 6.1.7.2, 6.2.x before 6.2.4, and 6.3.x before 6.3.0-RC4 mishandles secret keys with Google Authenticator for multifactor authentication.
- Record
CVE-2020-27178- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:P/A:N - Updated
- 2026-11-02
CVE List No score
Apereo CAS 5.3.x before 5.3.16, 6.x before 6.1.7.2, 6.2.x before 6.2.4, and 6.3.x before 6.3.0-RC4 mishandles secret keys with Google Authenticator for multifactor authentication.
- Record
CVE-2020-27178- Updated
- 2026-11-02
EUVDEUVD-2021-1832 No score
Apereo CAS 5.3.x before 5.3.16, 6.x before 6.1.7.2, 6.2.x before 6.2.4, and 6.3.x before 6.3.0-RC4 mishandles secret keys with Google Authenticator for multifactor authentication.
- Record
EUVD-2021-1832- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-q39c-5vh5-vw2p
Improper Authentication in Apereo CAS
Apereo CAS 5.3.x before 5.3.16, 6.x before 6.1.7.2, 6.2.x before 6.2.4, and 6.3.x before 6.3.0-RC4 mishandles secret keys with Google Authenticator for multifactor authentication.
- Record
GHSA-q39c-5vh5-vw2p- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-287
- Updated
- 2026-11-02
OSV
Apereo CAS 5.3.x before 5.3.16, 6.x before 6.1.7.2, 6.2.x before 6.2.4, and 6.3.x before 6.3.0-RC4 mishandles secret keys with Google Authenticator for multifactor authentication.
- Record
CVE-2020-27178- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Updated
- 2026-11-02
OSVGHSA-q39c-5vh5-vw2p
Improper Authentication in Apereo CAS
Apereo CAS 5.3.x before 5.3.16, 6.x before 6.1.7.2, 6.2.x before 6.2.4, and 6.3.x before 6.3.0-RC4 mishandles secret keys with Google Authenticator for multifactor authentication.
- Record
GHSA-q39c-5vh5-vw2p- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-287
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
org.apereo.cas:cas-server-webappMaven |
5.3.0 up to 5.3.16 | 5.3.16 |
org.apereo.cas:cas-server-webappMaven |
6.0.0 to 6.1.7.1 | 6.1.7.2 |
org.apereo.cas:cas-server-webappMaven |
6.2.0 up to 6.2.4 | 6.2.4 |
org.apereo.cas:cas-server-support-otp-mfa-coreMaven |
5.3.0 up to 5.3.16 | 5.3.16 |
org.apereo.cas:cas-server-support-otp-mfa-coreMaven |
6.0.0 to 6.1.7.1 | 6.1.7.2 |
org.apereo.cas:cas-server-support-otp-mfa-coreMaven |
6.2.0 up to 6.2.4 | 6.2.4 |
org.apereo.cas:cas-server-webappMaven |
5.3.0 up to 5.3.16, plus listed versions 5.3.15.3.105.3.115.3.125.3.12.1 Show 12 moreShow less5.3.135.3.145.3.155.3.15.15.3.25.3.35.3.45.3.55.3.65.3.75.3.85.3.9 |
5.3.16 |
org.apereo.cas:cas-server-webappMaven |
6.0.0 up to 6.1.7.2, plus listed versions 6.0.16.0.26.0.36.0.46.0.5 Show 20 moreShow less6.0.5.16.0.66.0.76.0.86.0.8.16.1.06.1.0-RC16.1.0-RC26.1.0-RC36.1.0-RC46.1.0-RC56.1.0-RC66.1.16.1.26.1.36.1.46.1.56.1.66.1.76.1.7.1 |
6.1.7.2 |
org.apereo.cas:cas-server-webappMaven |
6.2.0 up to 6.2.4, plus listed versions 6.2.16.2.26.2.3 |
6.2.4 |
org.apereo.cas:cas-server-support-otp-mfa-coreMaven |
6.0.0 up to 6.1.7.2, plus listed versions 6.0.16.0.26.0.36.0.46.0.5 Show 20 moreShow less6.0.5.16.0.66.0.76.0.86.0.8.16.1.06.1.0-RC16.1.0-RC26.1.0-RC36.1.0-RC46.1.0-RC56.1.0-RC66.1.16.1.26.1.36.1.46.1.56.1.66.1.76.1.7.1 |
6.1.7.2 |
org.apereo.cas:cas-server-support-otp-mfa-coreMaven |
6.2.0 up to 6.2.4, plus listed versions 6.2.16.2.26.2.3 |
6.2.4 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-27178 is a high vulnerability (CVSS 7.5) in Apereo Central Authentication Service, published October 16, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.22%, the 68th percentile. Fixed in org.apereo.cas:cas-server-webapp 5.3.16.