Code Injection in Oschina Fastjson

1) Code Injection

EUVDB-ID: #VU31188

Risk: High

CVSSv4.0: 8.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2017-18349

CWE-ID: CWE-94 - Improper Control of Generation of Code ('Code Injection')

Exploit availability: No

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to improper input validation in a crafted JSON request, as demonstrated by a crafted rmi:// URI in the dataSourceName field of HTTP POST data to the Pippo /json URI, which is mishandled in AjaxApplication.java. A remote attacker can send a specially crafted request and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation

Update to version 1.2.25.

Vulnerable software versions

Fastjson: 1.2.0 - 1.2.24

CPE2.3

• cpe:2.3:a:oschina:fastjson:1.2.0:*:*:*:*:*:*:*
• cpe:2.3:a:oschina:fastjson:1.2.1:*:*:*:*:*:*:*
• cpe:2.3:a:oschina:fastjson:1.2.2:*:*:*:*:*:*:*

External links

https://fortiguard.com/encyclopedia/ips/44059
https://github.com/alibaba/fastjson/wiki/security_update_20170315
https://github.com/pippo-java/pippo/issues/466

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.