XML External Entity injection in REXML gem for Ruby
| Risk | Medium |
| Patch available | YES |
| Number of vulnerabilities | 1 |
| CVE-ID | CVE-2021-28965 |
| CWE-ID | CWE-611 |
| Exploitation vector | Network |
| Public exploit | N/A |
| Vulnerable software Subscribe |
Ruby Universal components / Libraries / Scripting languages REXML Web applications / Modules and components for CMS |
| Vendor |
Ruby rubygems.org |
Security Bulletin
This security bulletin contains one medium risk vulnerability.
1) XML External Entity injection
EUVDB-ID: #VU52000
Risk: Medium
CVSSv3.1: 4.6 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-28965
CWE-ID:
CWE-611 - Improper Restriction of XML External Entity Reference ('XXE')
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to gain access to sensitive information.
The vulnerability exists due to insufficient validation of user-supplied XML input. A remote attacker can pass a specially crafted XML code to the affected application and view contents of arbitrary files on the system or initiate requests to external systems.
Successful exploitation of the vulnerability may allow an attacker to view contents of arbitrary file on the server or perform network scanning of internal and external infrastructure.
MitigationInstall updates from vendor's website.
Vulnerable software versionsRuby: 2.5.0 - 3.0.1
REXML: 3.1.8 - 3.2.4
External linkshttp://www.ruby-lang.org/en/news/2021/04/05/xml-round-trip-vulnerability-in-rexml-cve-2021-28965/
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.
