#VU56829 Input validation error in Go programming language - CVE-2021-29923
Published: September 22, 2021
Vulnerability identifier: #VU56829
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2021-29923
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
Go programming language
Go programming language
Software vendor:
Google
Description
The vulnerability allows a remote attacker to bypass implemented security restrictions.
The vulnerability exists due to insufficient validation of user-supplied input in net.ParseIP and net.ParseCIDR, as the Go interpreter does not properly consider extraneous zero characters at the beginning
of an IP address octet. A remote attacker can
bypass access control that is based on IP addresses, because of
unexpected octal interpretation.
Remediation
Install updates from vendor's website.
External links
- https://github.com/golang/go/issues/43389
- https://github.com/golang/go/issues/30999
- https://defcon.org/html/defcon-29/dc-29-speakers.html#kaoudis
- https://github.com/sickcodes/security/blob/master/advisories/SICK-2021-016.md
- https://golang.org/pkg/net/#ParseCIDR
- https://go-review.googlesource.com/c/go/+/325829/