Assessment
Why it matters
EPSS is 4.2%; technical severity is CVSS 9.8.
In PHP versions 7.3.x below 7.3.13 and 7.4.0 on Windows, when supplying custom headers to mail() function, due to mistake introduced in commit 78f4b4a2dcf92ddbccea1bb95f8390a18ac3342e, if the header is supplied in lowercase, this can result in double-freeing certain memory locations.
Who should care
- Teams operating Debian Linux, Fedora, PHP +1 more
- Vulnerability and exposure management teams
- Security operations teams monitoring exploitation activity
Response plan
What I would do
- Confirm whether Debian Linux, Fedora, PHP +1 more is present in the environment.
- Identify affected versions and establish whether vulnerable services are exposed or reachable.
- Debian Security advisory Dsa 4626
- Review relevant security telemetry for evidence of attempted or successful exploitation.
- Document the remediation decision and track it to verified completion.
Treatment intelligence
Remediation intelligence
Vendor sources are listed before government and third-party guidance. Confirm product applicability and change prerequisites before deployment.
Verification noteAutomated link verification has not completed for this guidance yet.
Technical details
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CWE
- CWE-415
- Affected versions
- Debian Debian Linux (Version 10.0); Fedoraproject Fedora (Version 30 | Version 31); PHP PHP (Start Including 7.3.0, End Including 7.3.13 | Version 7.4.0); Tenable Security Center (End Excluding 5.19.0)
- Fixed versions
- Tenable Security Center (Fixed from 5.19.0)
- Published
- 23 December 2019
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
Signal timeline
- CVE published
- Latest EPSS score: 4.2%
- Signal calculated at 17