CVE-2021-21708

Advisory lineage Upstream: 0 Downstream: 17
Modified
Published: 27 Feb 2022, 08:00
Last modified:17 Sept 2024, 03:18

Vulnerability Summary

Overall Risk (default)
high
70/100
CVSS Score
9.8 CRITICAL
v3.1 (nvd)
EPSS Score
0.22% LOW
0% probability -0.04%
KEV
Not listed
Ransomware
No reports
Public exploits
1 found
Dark Web
Not detected

Timeline

27 Feb 2022, 08:00
Published
Vulnerability first disclosed
17 Sept 2024, 03:18
Last Modified
Vulnerability information updated

Description

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.

CVSS Metrics

  • v3.1•HIGH•Score: 8.2CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L
  • v3.1•CRITICAL•Score: 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
  • v2.0•MEDIUM•Score: 6.8AV:N/AC:M/Au:N/C:P/I:P/A:P

EPSS Trends

Current EPSS score: 0.22%• Percentile: 44%

Techniques & Countermeasures

  • CWE-416•Use After Free

    The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Affected Systems

  • Unknown•PHP

    ≥ 7.4.x, < 7.4.28 | ≥ 8.0.X, < 8.0.16 | ≥ 8.1.X, < 8.1.3

  • Unknown•PHP

    ≥ 7.4.0, < 7.4.28 | ≥ 8.0.0, < 8.0.16 | ≥ 8.1.0, < 8.1.3

References (3)