CVE-2020-26138 FormField with square brackets in field name skips validation

What is CVE-2020-26138?

CVE-2020-26138 is a medium-severity missing authorization vulnerability in Silverstripe Silverstripe, published on 8 Jun 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

In SilverStripe through 4.6.0-rc1, a FormField with square brackets in the field name skips validation.

Weakness: CWE-20

Which versions are affected by CVE-2020-26138?

3 open source packages ship an affected version, including silverstripe/framework and silverstripe. It affects 1 product.

Products include Silverstripe Silverstripe.

How do I fix CVE-2020-26138?

Upgrade silverstripe/framework to 4.7.4 or later.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2020-26138 being exploited?

There is no known exploitation of CVE-2020-26138 in the wild and no public exploit code.

Other vulnerabilities in Silverstripe Silverstripe

• CVE-2007-2321 Other in n/a Critical 10.0
• CVE-2019-12204 Missing warning can lead to unauthenticated admin access in SilverStripe Critical 9.8
• CVE-2019-5715 Silverstripe Framework SQLi Vulnerability Critical 9.8
• CVE-2019-12437 Silverstripe CSRF Protection Bypass via GraphQL High 8.8
• CVE-2020-6164 Silverstripe CMS information disclosure High 7.5

All Silverstripe Silverstripe vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BIT-silverstripe-2020-26138, GHSA-7mv4-4xpg-xq44.