CVE-2021-21707 - CVE House
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Status published Medium CVE-2021-21707

Special characters break path parsing in XML functions

Vulnerability Description

In PHP versions 7.3.x below 7.3.33, 7.4.x below 7.4.26 and 8.0.x below 8.0.13, certain XML parsing functions, like simplexml_load_file(), URL-decode the filename passed to them. If that filename contains URL-encoded NUL character, this may cause the function to interpret this as the end of the filename, thus interpreting the filename differently from what the user intended, which may lead it to reading a different file than intended.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:

  • Reported by rawataman6525 at gmail dot com

References

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Affected Vendor

Affected Software

PHP
Vulnerable Versions:
7.3.x, 7.4.x, 8.0.X

Timeline

Official Publish: November 29th, 2021
Last Modified: September 17th, 2024
Added to House: July 21st, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Weaknesses (CWE)

CWE-159

MITRE ATT&CK TTPs

No associated TTPs found for this vulnerability.