CVE-2021-21707
Special characters break path parsing in XML functions
Severity Score
Exploit Likelihood
Affected Versions
Public Exploits
1Exploited in Wild
-Decision
Descriptions
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.
En PHP versiones 7.3.x anteriores a 7.3.33, 7.4.x anteriores a 7.4.26 y 8.0.x anteriores a 8.0.13, determinadas funciones de análisis de XML, como simplexml_load_file(), decodifican el nombre de archivo que les es pasado. Si ese nombre de archivo contiene un carácter NUL codificado en la URL, esto puede causar que la función lo interprete como el final del nombre de archivo, interpretando así el nombre de archivo de forma diferente a la que el usuario pretendía, lo que puede conllevar a una lectura de un archivo diferente al deseado
A flaw was found in php. The main cause of this vulnerability is improper input validation while parsing an Extensible Markup Language(XML) entity. A special character could allow an attacker to traverse directories. The highest threat from this vulnerability is confidentiality.
CVSS Scores
SSVC
- Decision:-
Timeline
- 2021-01-04 CVE Reserved
- 2021-11-29 CVE Published
- 2024-09-17 CVE Updated
- 2024-09-17 First Exploit
- 2024-10-07 EPSS Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
CWE
- CWE-20: Improper Input Validation
- CWE-159: Improper Handling of Invalid Use of Special Elements
CAPEC
References (7)
| URL | Tag | Source |
|---|---|---|
| https://lists.debian.org/debian-lts-announce/2022/12/msg00030.html | Issue Tracking |
|
| https://security.netapp.com/advisory/ntap-20211223-0005 | Third Party Advisory |
|
| URL | Date | SRC |
|---|---|---|
| https://bugs.php.net/bug.php?id=79971 | 2024-09-17 |
| URL | Date | SRC |
|---|---|---|
| https://www.tenable.com/security/tns-2022-09 | 2023-02-16 |
| URL | Date | SRC |
|---|---|---|
| https://www.debian.org/security/2022/dsa-5082 | 2023-02-16 | |
| https://access.redhat.com/security/cve/CVE-2021-21707 | 2022-11-08 | |
| https://bugzilla.redhat.com/show_bug.cgi?id=2026045 | 2022-11-08 |
Affected Vendors, Products, and Versions
| Vendor | Product | Version | Other | Status | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Vendor | Product | Version | Other | Status | <-- --> | Vendor | Product | Version | Other | Status |
| Php Search vendor "Php" | Php Search vendor "Php" for product "Php" | >= 7.3.0 < 7.3.33 Search vendor "Php" for product "Php" and version " >= 7.3.0 < 7.3.33" | - |
Affected
| ||||||
| Php Search vendor "Php" | Php Search vendor "Php" for product "Php" | >= 7.4.0 < 7.4.26 Search vendor "Php" for product "Php" and version " >= 7.4.0 < 7.4.26" | - |
Affected
| ||||||
| Php Search vendor "Php" | Php Search vendor "Php" for product "Php" | >= 8.0.0 < 8.0.13 Search vendor "Php" for product "Php" and version " >= 8.0.0 < 8.0.13" | - |
Affected
| ||||||
| Netapp Search vendor "Netapp" | Clustered Data Ontap Search vendor "Netapp" for product "Clustered Data Ontap" | - | - |
Affected
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| Debian Search vendor "Debian" | Debian Linux Search vendor "Debian" for product "Debian Linux" | 10.0 Search vendor "Debian" for product "Debian Linux" and version "10.0" | - |
Affected
| ||||||
| Debian Search vendor "Debian" | Debian Linux Search vendor "Debian" for product "Debian Linux" | 11.0 Search vendor "Debian" for product "Debian Linux" and version "11.0" | - |
Affected
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| Tenable Search vendor "Tenable" | Tenable.sc Search vendor "Tenable" for product "Tenable.sc" | < 5.21.0 Search vendor "Tenable" for product "Tenable.sc" and version " < 5.21.0" | - |
Affected
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