CVE-2021-21707 Special characters break path parsing in XML functions

2021-11-1500:00:00

CWE-159

php

www.cve.org

5.3 Medium

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

LOW

Integrity Impact

NONE

Availability Impact

NONE

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

7.1 High

AI Score

Confidence

High

0.001 Low

EPSS

Percentile

49.4%

JSON

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.

CNA Affected

[
  {
    "vendor": "PHP Group",
    "product": "PHP",
    "versions": [
      {
        "version": "7.3.x",
        "status": "affected",
        "lessThan": "7.3.33",
        "versionType": "custom"
      },
      {
        "version": "7.4.x",
        "status": "affected",
        "lessThan": "7.4.26",
        "versionType": "custom"
      },
      {
        "version": "8.0.X",
        "status": "affected",
        "lessThan": "8.0.13",
        "versionType": "custom"
      }
    ]
  }
]