CVE-2021-21708
What it is
In PHP versions 7.4.x below 7.4.28, 8.0.x below 8.0.16, and 8.1.x below 8.1.3, when using filter functions with FILTER_VALIDATE_FLOAT filter and min/max limits, if the filter fails, there is a possibility to trigger use of allocated memory after free, which can result it crashes, and potentially in overwrite of other memory chunks and RCE. This issue affects: code that uses FILTER_VALIDATE_FLOAT with min/max limits.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of data tampering.
- Exploit odds
- 3.0% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 3.0% in the next 30 days (EPSS).
- Severity: 8.2 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 3.0% · EPSS, next 30 days
- Weakness
- CWE-416 · Use after free
- Record status
- Modified
Affected
- PHP < 7.4.28
- PHP < 8.0.16
- PHP < 8.1.3
Attack profile CVSS 3.1 · 8.2
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- Low
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2021-21708.md and follow it. Check whether this project is affected by CVE-2021-21708. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
