CVE-2020-10687 — A flaw was discovered in all versions of Undertow before Undertow 2

A flaw was discovered in all versions of Undertow before Undertow 2.2.0.Final, where HTTP request smuggling related to CVE-2017-2666 is possible against HTTP/1.x and HTTP/2 due to permitting invalid characters in an HTTP request. This flaw allows an attacker to poison a web-cache

01What is this vulnerability?

A flaw was discovered in all versions of Undertow before Undertow 2.2.0.Final, where HTTP request smuggling related to CVE-2017-2666 is possible against HTTP/1.x and HTTP/2 due to permitting invalid characters in an HTTP request. This flaw allows an attacker to poison a web-cache, perform an XSS attack, or obtain sensitive information from request other than their own.

02Affected products

Vendor	Product	Versions
n	a / Undertow	Undertow 2.2.0.Final

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

08Timeline

• Published: 2020-09-23T12:30:43.000Z
• Last modified: 2024-08-04T11:06:11.126Z

09References

• bugzilla.redhat.com — https://bugzilla.redhat.com/show_bug.cgi?id=1785049
• lists.apache.org — https://lists.apache.org/thread.html/r6603513ea8afbf6857fd77ca5888ec8385d0af493b…
• security.netapp.com — https://security.netapp.com/advisory/ntap-20220210-0015/