Published:2015/03/03  Last Updated:2015/03/03

BestWebSoft Captcha plugin vulnerable to CAPTCHA authentication bypass


Wordpress plugin Captcha contains a CAPTCHA authentication bypass vulnerability.

Products Affected

  • Captcha V4.0.6 and earlier


Captcha provided by BestWebSoft is a plugin for WordPress. Captcha contains a CAPTCHA authentication bypass vulnerability (CWE-254).


If this vulnerability is exploited, an attacker may be able to successfully login to WordPress and access an administrative interface without authentication.


Update the Software
Update to the latest version according to the information provided by the developer.

Vendor Status

Vendor Link
BestWebSoft Captcha Changelog


JPCERT/CC Addendum

Vulnerability Analysis by JPCERT/CC

Analyzed on 2015.03.03 (CVSS Base Metrics)

What is CVSS?

Measures Severity Description
Access Vector(AV) Local (L) Adjacent Network (A) Network (N) A vulnerability exploitable with network access means the vulnerable software is bound to the network stack and the attacker does not require local network access or local access. Such a vulnerability is often termed "remotely exploitable".
Access Complexity(AC) High (H) Medium (M) Low (L) Specialized access conditions or extenuating circumstances do not exist.
Authentication(Au) Multiple (M) Single (S) None (N) Authentication is not required to exploit the vulnerability.
Confidentiality Impact(C) None (N) Partial (P) Complete (C) There is no impact to the confidentiality of the system.
Integrity Impact(I) None (N) Partial (P) Complete (C) Modification of some system files or information is possible, but the attacker does not have control over what can be modified, or the scope of what the attacker can affect is limited.
Availability Impact(A) None (N) Partial (P) Complete (C) There is no impact to the availability of the system.

Base Score:5.0


Other Information

JPCERT Reports
CERT Advisory
CPNI Advisory
CVE CVE-2014-9283
JVN iPedia JVNDB-2015-000029