CVE-2021-4240

Exploitation

Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.

SSVC decision

• ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.83% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 54.8% of scored records. A rank, not a probability.

NVD base score

5.3 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

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

NVD analysis status

Modified. NVD last modified this record on 2026-06-17.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2022-11-15 00:00Z3 YR AGO

Last updated

2025-04-15 13:14Z1 YR AGO

Reserved

2022-11-15

Assigning CNA

VulDB

Record state

PUBLISHED

Severity

Low (CVSS 2.6)

CNA CVSS vector

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

Weaknesses

• CWE-331Insufficient EntropyBase
• CWE-330Use of Insufficiently Random ValuesClass

Data version

5.1

Document digest

7e538d02719cf270d2d109f168dadf7c1f1139e6c2d628d403ef7a0b20b567d2

• huntr.devhttps://huntr.dev/bounties/2-phpservermon/phpservermon/
• github.comhttps://github.com/phpservermon/phpservermon/commit/3daa804d5f56c55b3ae13bfac368bb84ec632193
• vuldb.comhttps://vuldb.com/?id.213717