Vulnerability identifier: #VU37874

Vulnerability risk: High

CVSSv3.1: 7.1 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-4995

CWE-ID: CWE-502

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 non-authenticated attacker to execute arbitrary code.

An issue was discovered in Pivotal Spring Security 4.2.0.RELEASE through 4.2.2.RELEASE, and Spring Security 5.0.0.M1. When configured to enable default typing, Jackson contained a deserialization vulnerability that could lead to arbitrary code execution. Jackson fixed this vulnerability by blacklisting known "deserialization gadgets." Spring Security configures Jackson with global default typing enabled, which means that (through the previous exploit) arbitrary code could be executed if all of the following is true: (1) Spring Security's Jackson support is being leveraged by invoking SecurityJackson2Modules.getModules(ClassLoader) or SecurityJackson2Modules.enableDefaultTyping(ObjectMapper); (2) Jackson is used to deserialize data that is not trusted (Spring Security does not perform deserialization using Jackson, so this is an explicit choice of the user); and (3) there is an unknown (Jackson is not blacklisting it already) "deserialization gadget" that allows code execution present on the classpath. Jackson provides a blacklisting approach to protecting against this type of attack, but Spring Security should be proactive against blocking unknown "deserialization gadgets" when Spring Security enables default typing.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Spring Security: 4.2.0 - 5.0.0

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External links
http://www.securityfocus.com/bid/99080
http://lists.apache.org/thread.html/4641ed8616ccc2c1fbddac2c3dc9900c96387bc226eaf0232d61909b@%3Ccommits.cassandra.apache.org%3E
http://pivotal.io/security/cve-2017-4995

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

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