Security readout for executives and security teams
Plain-English summary
This is a narrow libcurl certificate-checking flaw affecting Windows CE builds that use the schannel TLS backend. A malicious server certificate with a wildcard name could make the client read outside intended memory, causing a crash or possible information exposure.
Executive priority
Treat as targeted remediation for legacy or embedded Windows CE environments, not a broad enterprise emergency. Prioritize affected systems that connect to untrusted TLS endpoints or are hard to patch.
Technical view
The issue is in lib/vtls/schannel.c verify_certificate in libcurl 7.30.0 through 7.51.0 on Windows CE schannel builds. Wildcard certificate name handling can trigger an out-of-bounds read during TLS certificate verification. Published metadata does not provide CVSS, CWE, or detailed exploitability scoring.
Likely exposure
Exposure appears limited to software bundling affected libcurl versions on Windows CE with the schannel TLS backend. Standard libcurl deployments outside that build target are not identified as affected in the provided sources.
Exploitation context
The source bundle does not cite active exploitation, and KEV is false. The attack condition is remote interaction with certificate verification against a crafted wildcard certificate name, with stated impacts of sensitive information exposure, denial of service, or unspecified impact.
Researcher notes
Evidence is concise and old. The affected range and build condition are clear, but severity scoring, exploit prevalence, and product-specific impact are not provided. Avoid broad assumptions beyond Windows CE schannel libcurl builds.
Mitigation direction
- Inventory products using libcurl 7.30.0 through 7.51.0 on Windows CE.
- Update libcurl to a version containing the curl advisory fix.
- Apply the referenced curl patch where upgrading is not immediately possible.
- Check vendor guidance for embedded or third-party products bundling libcurl.
Validation and detection
- Confirm whether any asset uses Windows CE with libcurl schannel TLS support.
- Check bundled libcurl versions in affected applications and firmware.
- Review vendor advisories for appliances or embedded software using libcurl.
- Verify remediation by confirming a fixed libcurl version or applied patch.
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.
CVE-2016-9953 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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 and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://curl.haxx.se/CVE-2016-9952.patchCVE reference · x_refsource_CONFIRM
- https://curl.haxx.se/docs/adv_20161221C.htmlCVE 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.