VulnerabilityModified

CVE-2017-3203

HIGH 8.1EPSS 6.23%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (6.23%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

The Java implementations of AMF3 deserializers in Pivotal/Spring Spring-flex derive class instances from java.io.Externalizable rather than the AMF3 specification's recommendation of flash.utils.IExternalizable. A remote attacker with the ability to spoof or control an RMI server connection may be able to send serialized Java objects that execute arbitrary code when deserialized.

CVSS 3.0: 8.1 HIGHCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS: 6.23% probability · 94th percentile
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Weakness: CWE-502
Affected: pivotal/spring-flex
Source: cret@cert.org

EPSS trend

EPSS 6.2% since 27 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

http://www.securityweek.com/flaws-java-amf-libraries-allow-remote-code-executionThird Party Advisory
https://codewhitesec.blogspot.com/2017/04/amf.htmlExploit, Mitigation, Third Party Advisory
https://www.kb.cert.org/vuls/id/307983Third Party Advisory, US Government Resource
https://www.securityfocus.com/bid/97376Third Party Advisory, VDB Entry
http://www.securityweek.com/flaws-java-amf-libraries-allow-remote-code-executionThird Party Advisory
https://codewhitesec.blogspot.com/2017/04/amf.htmlExploit, Mitigation, Third Party Advisory
https://www.kb.cert.org/vuls/id/307983Third Party Advisory, US Government Resource
https://www.securityfocus.com/bid/97376Third Party Advisory, VDB Entry

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.