CVE-2020-12443
9.8
CRITICAL · CVSS 3.1 · EPSS 3.7% (pctl 89)
In your normal cycle
Critical by CVSS (9.8), but no sign of active exploitation.
Description
BigBlueButton before 2.2.6 allows remote attackers to read arbitrary files because the presfilename (lowercase) value can be a .pdf filename while the presFilename (mixed case) value has a ../ sequence. This can be leveraged for privilege escalation via a directory traversal to bigbluebutton.properties. NOTE: this issue exists because of an ineffective mitigation to CVE-2020-12112 in which there was an attempted fix within an NGINX configuration file, without considering that the relevant part of NGINX is case-insensitive.
Scoring
| CVSS | 9.8 (CRITICAL, v3.1) |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 3.66% — more likely to be exploited than 89% of all CVEs |
| Weakness | CWE-22 |
| On CISA KEV | no |
| Public exploit | none known |
| Published | 2020-04-29 |
| Last modified | 2026-06-17 |
Affected (1)
| Vendor | Product |
|---|---|
| bigbluebutton | bigbluebutton |
References
→ the Explorer · watch your stack · NVD