myBB version 1.6.4 was distributed with an unauthorized backdoor embedded in the source code. The backdoor allowed remote attackers to execute arbitrary PHP code by injecting payloads into a specially crafted collapsed cookie. This vulnerability was introduced during packaging and was not part of the intended application logic. Exploitation requires no authentication and results in full compromise of the web server under the context of the web application.

Multiple unspecified vulnerabilities in MyBulletinBoard (MyBB) before 1.0.2 have unspecified impact and attack vectors, related to (1) admin/moderate.php, (2) admin/themes.php, (3) inc/functions.php, (4) inc/functionsupload.php, (5) printthread.php, and (6) usercp.php, and probably related to SQL injection. NOTE: it is likely that this issue subsumes CVE-2005-4602 and CVE-2005-4603. However, since the vendor advisory is vague and additional files are mentioned, is is likely that this contains at least one distinct vulnerability from CVE-2005-4602 and CVE-2005-4603.

Unspecified vulnerability in MyBB (aka MyBulletinBoard) before 1.8.4 has unknown attack vectors related to "Group join request notifications sent to wrong group leaders."

Unspecified vulnerability in MyBB before 1.6.5 has unknown impact and attack vectors, related to an "unparsed user avatar in the buddy list."

SQL injection vulnerability in the Group Promotions module in the admin control panel in MyBB (aka MyBulletinBoard) before 1.6.18 and 1.8.x before 1.8.6 and MyBB Merge System before 1.8.6 allows remote attackers to execute arbitrary SQL commands via unspecified vectors.

Installer RCE on settings file write in MyBB before 1.8.22.

The installer in MyBB before 1.8.13 allows remote attackers to execute arbitrary code by writing to the configuration file.

SQL injection vulnerability in the users data handler in MyBB (aka MyBulletinBoard) before 1.8.8 and MyBB Merge System before 1.8.8 allows remote attackers to execute arbitrary SQL commands via unspecified vectors.

MyBB (aka MyBulletinBoard) before 1.8.7 and MyBB Merge System before 1.8.7 allow attackers to have unspecified impact via vectors related to low adminsid and sid entropy.

SQL injection vulnerability in the moderation tool in MyBB (aka MyBulletinBoard) before 1.8.7 and MyBB Merge System before 1.8.7 might allow remote attackers to execute arbitrary SQL commands via unspecified vectors.

MyBB (aka MyBulletinBoard) before 1.8.8 and MyBB Merge System before 1.8.8 allow remote attackers to have unspecified impact via vectors related to "loose comparison false positives."

newreply.php in MyBB (aka MyBulletinBoard) before 1.8.7 and MyBB Merge System before 1.8.7 allows remote attackers to have unspecified impact by leveraging a missing permission check.

MyBB is free and open source forum software. Prior to 1.8.40, the Contact module does not validate a redirect URL or protocol correctly, resulting in an open redirect and reflected JavaScript code injection. contact.php accepts the redirect target from the from HTTP parameter in $mybb->input['from'] or the Referer HTTP header in $SERVER['HTTPREFERER'] and passes it to redirect() without sufficient verification. A javascript: URI becomes the target of the Click here if you don't want to wait any longer link because $forceredirect is true, allowing script execution when a victim selects the link. This issue is fixed in version 1.8.40.

MyBB 1.8.32 contains a chained vulnerability that allows authenticated administrators to bypass avatar upload restrictions and execute arbitrary code. Attackers can modify upload path settings, upload a malicious PHP-embedded image file, and execute commands through the language configuration editing interface.

Trash Bin plugin 1.1.3 for MyBB has cross-site scripting (XSS) via a thread subject and a cross-site request forgery (CSRF) via a post subject.

SQL Injection vulnerablity in MyBB before 1.8.26 via theme properties included in theme XML files.

SQL Injection vulnerability in MyBB before 1.8.26 via poll vote count. (issue 1 of 3).

In MyBB before version 1.8.24, the custom MyCode (BBCode) for the visual editor doesn't escape input properly when rendering HTML, resulting in a DOM-based XSS vulnerability. The weakness can be exploited by pointing a victim to a page where the visual editor is active (e.g. as a post or Private Message) and operates on a maliciously crafted MyCode message. This may occur on pages where message content is pre-filled using a GET/POST parameter, or on reply pages where a previously saved malicious message is quoted. After upgrading MyBB to 1.8.24, make sure to update the version attribute in the codebuttons template for non-default themes to serve the latest version of the patched jscripts/bbcodessceditor.js file.

MyBB is free and open source forum software. Prior to 1.8.40, the user datahandler does not properly validate checkbox and multiselect profile field types, resulting in stored JavaScript code injection. UserDataHandler::verifyprofilefields() only performs the specialized validation when isarray($profilefields[$field]) is true. A non-array profilefields[fidX] value instead of the expected profilefields[fidX][] shape falls through to generic text handling and is stored without verification. The affected value is then rendered directly by member.php and inc/functionspost.php rather than processed by the MyCode parser. The uniquely identifying implementation details include inc/datahandlers/user.php. This issue is fixed in version 1.8.40.

In MyBB before 1.8.21, an attacker can exploit a parsing flaw in the Private Message / Post renderer that leads to [video] BBCode persistent XSS to take over any forum account, aka a nested video MyCode issue.

Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority. This CVE was assigned on the basis that the permission system allows a limited administrator to grant privileges exceeding their own authorization scope, potentially constituting an insecure default configuration. Following a dispute, the MITRE TL-Root determined the behavior reflects documented and intended product design rather than a security vulnerability.

xmlhttp.php in MyBB (aka MyBulletinBoard) before 1.6.18 and 1.8.x before 1.8.6 and MyBB Merge System before 1.8.6 allows remote attackers to bypass intended access restrictions via vectors related to the forum password.

MyBB before 1.8.11 allows remote attackers to bypass an SSRF protection mechanism.

An issue in MyBB 1.8.38 allows a remote attacker to obtain sensitive information via the Import a Theme function. NOTE: the Supplier disputes this because of the allowed actions of Board administrators and because of SSRF mitigation.

An issue in MyBB 1.8.38 allows a remote attacker to obtain sensitive information via the Change Avatar function. NOTE: the Supplier disputes this because of the allowed actions of Board administrators and because of SSRF mitigation.

An issue in MyBB 1.8.38 allows a remote attacker to obtain sensitive information via the Mail function. NOTE: the Supplier disputes this because of the allowed actions of Board administrators and because of SSRF mitigation.

An issue in MyBB 1.8.38 allows a remote attacker to obtain sensitive information via the Add Mycode function. NOTE: the Supplier disputes this because of the allowed actions of Board administrators and because of SSRF mitigation.

Multiple SQL injection vulnerabilities in MyBulletinBoard (MyBB) before 1.0 allow remote attackers to execute arbitrary SQL commands via the (1) month, (2) day, and (3) year parameters in an addevent action in calendar.php; (4) threadmode and (5) showcodebuttons in an options action in usercp.php; (6) list parameter in an editlists action to usercp.php; (7) rating parameter in a rate action in member.php; and (8) rating parameter in either showthread.php or ratethread.php.

Multiple SQL injection vulnerabilities in MyBB (aka MyBulletinBoard) before 1.6.7 allow remote administrators to execute arbitrary SQL commands via unspecified vectors in the (1) user search or (2) Mail Log in the Admin Control Panel (ACP).

SQL injection vulnerability in the User Inline Moderation feature in the Admin Control Panel (ACP) in MyBB (aka MyBulletinBoard) before 1.6.7 allows remote administrators to execute arbitrary SQL commands via unspecified vectors.