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GHSA-9c3j-xm6v-j7j3high7.6

MantisBT has a Content Security Policy bypass via attachments

Impact

Given any pre-existing XSS / HTML injection vulnerability, an attacker can bypass the Content Security Policy's _script-src_ directive by uploading a crafted attachment to any issue that, when accessed via the _file_download.php_ link, will be downloaded with a valid JavaScript MIME type resulting in script execution.

Source excerpt · OSV
Applies when

Non-JavaScript MIME types will not get imported in a <script> tag by the browser, due to response header X-Content-Type-Options being set to nosniff, which requires all imported JavaScript files to be a valid JavaScript MIME type.

Affected packages

Start with the recorded fix for your release branch. Check your installed version and test compatibility before upgrading. Fixing this advisory does not rule out other vulnerabilities in the release.

mantisbt/mantisbt Packagist
Affected rangeRecorded fix
Earlier releases before 2.28.2Ecosystem versions2.28.2

Version evidence: OSV · GHSA-9c3j-xm6v-j7j3

View original version evidence (76 explicit versions)

Original source description

Given any pre-existing XSS / HTML injection vulnerability, an attacker can bypass the Content Security Policy's script-src directive by uploading a crafted attachment to any issue that, when accessed via the file_download.php link, will be downloaded with a valid JavaScript MIME type resulting in script execution.

The uploaded payload must be sniffed as a valid JavaScript MIME type by PHP finfo (see file_create_finfo() API function). Non-JavaScript MIME types will not get imported in a <script> tag by the browser, due to response header X-Content-Type-Options being set to nosniff, which requires all imported JavaScript files to be a valid JavaScript MIME type.

Impact

Cross-site scripting

Patches

  • 9e3bee2e7b909f4e3596985892b8bc8bee9e0bfe

Workarounds

None

Credits

Thanks to siunam (Tang Cheuk Hei) for discovering and responsibly reporting the issue.

References