Security readout for executives and security teams
Plain-English summary
CVE-2019-11049 is a PHP memory-management flaw affecting Windows builds of PHP 7.3.x before 7.3.13 and PHP 7.4.0. A specific mail() custom-header condition can cause a double free, potentially crashing the process and possibly affecting data integrity. This is mainly a legacy exposure issue for systems still running those PHP versions.
Executive priority
Treat this as a moderate-priority legacy remediation item. It is not documented as actively exploited in the provided sources, but unsupported or outdated PHP on public services creates avoidable operational risk and should be removed from production exposure.
Technical view
The bug is CWE-415 double free in PHP mail() handling on Windows. When custom headers are supplied in lowercase, PHP may release a string with refcount 1 twice. The CVSS 3.1 score is 6.5 with high attack complexity, no privileges or user interaction, no confidentiality impact, low integrity impact, and high availability impact.
Likely exposure
Exposure is most likely in Windows-hosted PHP applications or products using PHP 7.3.x before 7.3.13 or PHP 7.4.0, especially where application code invokes mail() with custom headers. Linux package advisories exist, but the provided CVE description specifically calls out Windows behavior.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. The condition is narrow and has high attack complexity, but reachable mail-sending paths in public applications could turn a bug into service disruption if the affected PHP runtime remains deployed.
Researcher notes
Focus validation on version, platform, and reachability of mail() custom-header paths. The public description identifies the lowercase-header condition and double-free class, but evidence in the bundle is insufficient to claim practical exploitation, widespread impact, or product-specific behavior beyond cited vendor advisories.
Mitigation direction
- Upgrade affected PHP 7.3.x Windows deployments to at least 7.3.13 or a supported fixed release.
- Move PHP 7.4.0 systems to a vendor-supported release containing the security fix.
- Apply relevant Debian, Fedora, NetApp, or product vendor security updates where applicable.
- Prioritize internet-facing applications that send email through PHP mail().
- Review vendor guidance before applying compensating controls not named in advisories.
Validation and detection
- Inventory servers and appliances for PHP 7.3.x before 7.3.13 or PHP 7.4.0.
- Confirm whether affected systems are Windows-hosted PHP runtimes.
- Search application code for mail() usage with custom headers.
- Check package manager or vendor advisory status for installed PHP builds.
- Review crash logs around mail-sending paths for unexplained PHP process failures.
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-415: 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-2019-11049 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
- Medium
- CVSS
- 6.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H
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:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H2.24.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://bugs.php.net/bug.php?id=78943CVE reference · x_refsource_MISC
- https://security.netapp.com/advisory/ntap-20200103-0002/CVE reference · x_refsource_CONFIRM
- FEDORA-2019-437d94e271CVE reference · vendor-advisory, x_refsource_FEDORA
- FEDORA-2019-a54a622670CVE reference · vendor-advisory, x_refsource_FEDORA
- 20200218 [SECURITY] [DSA 4626-1] php7.3 security updateCVE reference · mailing-list, x_refsource_BUGTRAQ
- DSA-4626CVE reference · vendor-advisory, x_refsource_DEBIAN
- https://www.tenable.com/security/tns-2021-14CVE reference · x_refsource_CONFIRM
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.
Double Free
Double Free represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.