CVE-2021-21707
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.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 25.3%, higher than 98% of all known CVEs. Patch or mitigate before the next change window.
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.
- CVSS 3.1
- 5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- EPSS
- 25.31% probability · 98th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-159
- Affected
- php/php · netapp/clustered data ontap · debian/debian linux · tenable/tenable.sc
- Source
- security@php.net
EPSS 25.3% since 3 November 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://bugs.php.net/bug.php?id=79971Exploit, Issue Tracking, Patch, Release Notes, Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2022/12/msg00030.htmlIssue Tracking, Mailing List
- https://security.netapp.com/advisory/ntap-20211223-0005/Third Party Advisory
- https://www.debian.org/security/2022/dsa-5082Third Party Advisory
- https://www.tenable.com/security/tns-2022-09Patch, Release Notes, Third Party Advisory
- https://bugs.php.net/bug.php?id=79971Exploit, Issue Tracking, Patch, Release Notes, Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2022/12/msg00030.htmlIssue Tracking, Mailing List
- https://security.netapp.com/advisory/ntap-20211223-0005/Third Party Advisory
- https://www.debian.org/security/2022/dsa-5082Third Party Advisory
- https://www.tenable.com/security/tns-2022-09Patch, Release Notes, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.