Vulnerability Details : CVE-2019-12831
Potential exploit
In MyBB before 1.8.21, an attacker can abuse a default behavior of MySQL on many systems (that leads to truncation of strings that are too long for a database column) to create a PHP shell in the cache directory of a targeted forum via a crafted XML import, as demonstrated by truncation of aaaaaaaaaaaaaaaaaaaaaaaaaa.php.css to aaaaaaaaaaaaaaaaaaaaaaaaaa.php with a 30-character limit, aka theme import stylesheet name RCE.
Vulnerability category: Input validation
Products affected by CVE-2019-12831
- cpe:2.3:a:mybb:mybb:*:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2019-12831
0.55%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 65 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2019-12831
| Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
|---|---|---|---|---|---|---|
|
6.5
|
MEDIUM | AV:N/AC:L/Au:S/C:P/I:P/A:P |
8.0
|
6.4
|
NIST | |
|
7.2
|
HIGH | CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H |
1.2
|
5.9
|
NIST |
CWE ids for CVE-2019-12831
-
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.Assigned by: nvd@nist.gov (Primary)
References for CVE-2019-12831
-
https://blog.ripstech.com/2019/mybb-stored-xss-to-rce/
MyBB <= 1.8.20: From Stored XSS to RCEExploit;Vendor Advisory
-
https://blog.mybb.com/2019/06/10/mybb-1-8-21-released-security-maintenance-release/
MyBB 1.8.21 Released — Security & Maintenance Release | MyBB BlogRelease Notes;Vendor Advisory
Jump to