#VU28464 Improper Verification of Cryptographic Signature in Spring Security - CVE-2020-5407

Vulnerability identifier: #VU28464

Vulnerability risk: Medium

CVSSv4.0: 6.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-5407

CWE-ID: CWE-347

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Spring Security
Server applications / Frameworks for developing and running applications

Vendor: VMware, Inc

Description

The vulnerability allows a remote attacker to compromise the target system.

The vulnerability exists due to a signature wrapping issue during SAML response validation when using the "spring-security-saml2-service-provider" component. A remote authenticated attacker can carefully modify an otherwise valid SAML response and append an arbitrary assertion that Spring Security will accept as valid.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Spring Security: 5.2.0 - 5.2.3, 5.3.0 - 5.3.1

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External links
https://lists.apache.org/thread.html/r73af928cf64bebf78b7fa4bc56a5253273ec7829f5f5827f64c72fc7@%3Cissues.servicemix.apache.org%3E
https://lists.apache.org/thread.html/ra19a4e7236877fe12bfb52db07b27ad72d9e7a9f5e27bba7e928e18a@%3Cdev.geode.apache.org%3E
https://lists.apache.org/thread.html/rd99601fbca514f214f88f9e53fd5be3cfbff05b350c994b4ec2e184c@%3Cdev.geode.apache.org%3E
https://tanzu.vmware.com/security/cve-2020-5407
https://github.com/spring-projects/spring-security/tree/5.2.3.RELEASE/samples/boot/saml2login
https://docs.spring.io/spring-security/site/docs/5.2.3.RELEASE/reference/html5/#saml2

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.