Double Free in Microsoft Windows

CVE-2019-11049

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.

Vulnerability class: Double Free

EPSS: 0.044 (90.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2019-11049?
CVE-2019-11049 is a medium-severity vulnerability in Microsoft Windows, classified under Double Free. CVSS score: 6.5/10. Published 2019-12-23.
How severe is CVE-2019-11049?
Medium severity. CVSS v3 base score is 6.5 out of 10.
Is CVE-2019-11049 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.