CVE-2021-26918
The ProBot bot through 2021-02-08 for Discord might allow attackers to interfere with the intended purpose of the "Send an image when a user joins the server" feature (or possibly have unspecified other impact) because the uploader web service allows…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.58%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
The ProBot bot through 2021-02-08 for Discord might allow attackers to interfere with the intended purpose of the "Send an image when a user joins the server" feature (or possibly have unspecified other impact) because the uploader web service allows double extensions (such as .html.jpg) with the text/html content type. NOTE: there may not be cases in which an uploader web service is customer controlled; however, the nature of the issue has substantial interaction with customer controlled configuration. NOTE: the vendor states "This is just an uploader (like any other one) which uploads files to cloud storage and accepts various file types. There is no kind of vulnerability and it won't compromise either the client side or the server side.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 2.58% probability · 84th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-434
- Affected
- probot/bot
- Source
- cve@mitre.org
References
- http://packetstormsecurity.com/files/161347/Discord-Probot-Arbitrary-File-Upload.htmlExploit, Third Party Advisory, VDB Entry
- https://raw.githubusercontent.com/TheLastVvV/Vulnerability-Reports-and-CVE/main/Reports/Discord%20Probot%20-%20Unrestricted%20File%20Upload.txtExploit, Third Party Advisory
- http://packetstormsecurity.com/files/161347/Discord-Probot-Arbitrary-File-Upload.htmlExploit, Third Party Advisory, VDB Entry
- https://raw.githubusercontent.com/TheLastVvV/Vulnerability-Reports-and-CVE/main/Reports/Discord%20Probot%20-%20Unrestricted%20File%20Upload.txtExploit, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.