CVE-2020-36828
Description
A vulnerability was found in DiscuzX up to 3.4-20200818. It has been classified as problematic. Affected is the function show_next_step of the file upload/install/include/install_function.php. The manipulation of the argument uchidden leads to cross site scripting. It is possible to launch the attack remotely. Upgrading to version 3.4-20210119 is able to address this issue. The name of the patch is 4a9673624f46f7609486778ded9653733020c567. It is recommended to upgrade the affected component. The identifier of this vulnerability is VDB-258612.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
DiscuzX up to 3.4-20200818 has a reflected XSS vulnerability in the installer via the 'uchidden' parameter, allowing remote attackers to inject arbitrary scripts.
Vulnerability
A reflected cross-site scripting (XSS) vulnerability exists in DiscuzX versions up to 3.4-20200818. The function show_next_step in upload/install/include/install_function.php does not properly sanitize the uchidden parameter before rendering it in the installer page. An attacker can inject malicious JavaScript code through this parameter, which will be executed in the context of the victim's browser [1].
Exploitation
To exploit this vulnerability, an attacker can craft a URL with a malicious uchidden value and trick a user into clicking it. The attack is remote and does not require authentication, as it targets the installer interface, which may be accessible during the initial setup or upgrades. The only prerequisite is that the target system has not applied the fix [1].
Impact
Successful exploitation allows the attacker to execute arbitrary JavaScript in the victim's browser, potentially leading to session hijacking, defacement, or theft of sensitive information. The impact is limited by the context of the installer page, which may not contain high-value data, but it represents a security risk for administrators performing updates [1].
Mitigation
The vulnerability is patched in DiscuzX version 3.4-20210119. The fix, committed in 4a9673624f46f7609486778ded9653733020c567, validates and sanitizes the uchidden parameter by ensuring it contains expected fields and applying dhtmlspecialchars. Users are advised to upgrade to the latest version or apply the patch [1].
AI Insight generated on May 20, 2026. Synthesized from this CVE's description and the cited reference URLs; citations are validated against the source bundle.
Affected products
1Patches
14a9673624f46!187 修复 install.php中uchidden参数的XSS漏洞
1 file changed · +10 −0
upload/install/include/install_function.php+10 −0 modified@@ -348,6 +348,16 @@ function show_env_result(&$env_items, &$dirfile_items, &$func_items, &$filesock_ function show_next_step($step, $error_code) { global $uchidden; + + if(!empty($uchidden)) { + $uc_info_transfer = unserialize(urldecode($uchidden)); + if(!isset($uc_info_transfer['ucapi']) && !isset($uc_info_transfer['ucfounderpw'])){ + $uchidden = ''; + } else { + $uchidden = dhtmlspecialchars($uchidden); + } + } + echo "<form action=\"index.php\" method=\"post\">\n"; echo "<input type=\"hidden\" name=\"step\" value=\"$step\" />"; if(isset($GLOBALS['hidden'])) {
Vulnerability mechanics
Generated on May 9, 2026. Inputs: CWE entries + fix-commit diffs from this CVE's patches. Citations validated against bundle.
References
3News mentions
0No linked articles in our index yet.