#VU11648 Improper verification of cryptographic signature in Ruby - CVE-2018-1000076

Vulnerability identifier: #VU11648

Vulnerability risk: Low

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2018-1000076

CWE-ID: CWE-347

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Ruby
Universal components / Libraries / Scripting languages

Vendor: Ruby

Description
The vulnerability allows a remote attacker to write arbitrary files on the target system.

The weakness exists in package.rb due to improper verification of cryptographic signature. A remote attacker can install mis-signed gem, as the tarball would contain multiple gem signatures.

Mitigation
Update to version 2.7.6.

Vulnerable software versions

Ruby: 2.2.0 - 2.5.0

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External links
https://blog.rubygems.org/2018/02/15/2.7.6-released.html

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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.