PT-2020-16398 · Google+2 · Go+2

Published 2020-12-17 · Updated 2022-02-11 · CVE-2020-26276

Positive Technologies (AI Summary)

CVSS v3.1

10

Critical

Base vector

AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions Fleet versions prior to 3.5.1

Description The issue arises from problems in Go's standard library XML parsing, allowing an attacker to mutate a valid SAML response and modify the trusted document. This can result in allowing unverified logins from a SAML IdP. Users that configure Fleet with SSO login may be vulnerable to this issue.

Recommendations For versions prior to 3.5.1, upgrade to version 3.5.1 to resolve the issue. If upgrade to 3.5.1 is not possible, disable SSO authentication in Fleet as a temporary workaround.

Fix

Authentication Bypass by Spoofing

Weakness Enumeration

CWE-290

Related Identifiers

ALT-PU-2021-1107

CVE-2020-26276

GHSA-W3WF-CFX3-6GCX

Affected Products

Alt Linux

Fleet

Go

References · 14

• https://github.com/fleetdm/fleet/commit/57812a532e5f749c8e18c6f6a652eca65c083607 · Patch
• https://osv.dev/vulnerability/CVE-2020-26276 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2020-26276 · Security Note
• https://osv.dev/vulnerability/GHSA-w3wf-cfx3-6gcx · Vendor Advisory
• https://github.com/fleetdm/fleet/security/advisories/GHSA-w3wf-cfx3-6gcx · Note
• https://github.com/fleetdm/fleet/blob/master/CHANGELOG.md#fleet-351-dec-14-2020 · Note
• https://github.com/mattermost/xml-roundtrip-validator · Note
• https://t.me/cvenotify/7391 · Telegram Post
• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-26276 · Note
• https://t.me/cibsecurity/21015 · Telegram Post
• https://mattermost.com/blog/coordinated-disclosure-go-xml-vulnerabilities · Note
• https://t.me/cvenotify/7264 · Telegram Post
• https://t.me/cvenotify/7267 · Telegram Post
• https://cwe.mitre.org/data/definitions/290.html · Note