Security readout for executives and security teams
Plain-English summary
phpservermon had weak password reset token generation. An attacker meeting the required conditions could potentially predict reset tokens, creating limited confidentiality risk. Public exploit disclosure is reported, but the provided sources do not show CISA KEV listing or confirmed active exploitation.
Executive priority
Treat this as a low-priority but real hygiene fix. The impact is limited, but password reset weaknesses can undermine account trust. Patch during the next maintenance window, sooner if phpservermon is exposed to untrusted adjacent networks.
Technical view
CVE-2021-4240 affects generatePasswordResetToken in src/psm/Service/User.php. It is classified as CWE-331 for predictable random number generation. CVSS 3.1 is 2.6: adjacent vector, high complexity, low privileges, no user interaction, and low confidentiality impact. Patch commit 3daa804d5f56c55b3ae13bfac368bb84ec632193 is cited.
Likely exposure
Exposure is limited to organizations running phpservermon builds containing the vulnerable User.php implementation. The bundle does not identify exact affected versions or CPEs, so teams should compare deployed code or release lineage against the referenced patch.
Exploitation context
VulDB reports that exploit details were publicly disclosed and may be used. The bundle does not provide KEV status or cited confirmation of active exploitation. The CVSS vector indicates exploitation requires adjacent access, low privileges, and high complexity.
Researcher notes
The source bundle lacks exact affected version ranges, so validation should focus on code comparison to the cited commit. Do not assume broader products or versions are affected. Public disclosure is reported, but active exploitation is not established here.
Mitigation direction
- Apply phpservermon patch commit 3daa804d5f56c55b3ae13bfac368bb84ec632193 or a release containing it.
- Check phpservermon upstream advisories or release notes for supported fixed versions.
- Review password reset activity where phpservermon is deployed.
- Limit access to phpservermon administrative surfaces where operationally feasible.
Validation and detection
- Inventory phpservermon deployments and identify the deployed source or package version.
- Confirm src/psm/Service/User.php includes the referenced password reset token fix.
- Verify password reset tokens are generated with non-predictable randomness after patching.
- Check logs for abnormal password reset requests before remediation.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-331: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-4240 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Low
- CVSS
- 2.6 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N1.21.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
2.6LowVector: CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://huntr.dev/bounties/2-phpservermon/phpservermon/CVE reference
- https://github.com/phpservermon/phpservermon/commit/3daa804d5f56c55b3ae13bfac368bb84ec632193CVE reference
- https://vuldb.com/?id.213717CVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Insufficient Entropy
Insufficient Entropy represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.