CVE-2016-9952
The verify_certificate function in lib/vtls/schannel.c in libcurl 7.30.0 through 7.51.0, when...
The verify_certificate function in lib/vtls/schannel.c in libcurl 7.30.0 through 7.51.0, when built for Windows CE using the schannel TLS backend, makes it easier for remote attackers to conduct man-in-the-middle attacks via a crafted wildcard SAN in a server certificate, as demonstrated by "*.com."
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List
The verify_certificate function in lib/vtls/schannel.c in libcurl 7.30.0 through 7.51.0, when built for Windows CE using the schannel TLS backend, makes it easier for remote attackers to conduct man-in-the-middle attacks via a crafted wildcard SAN in a server certificate, as demonstrated by "*.com."
- Record
CVE-2016-9952- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-295
- Updated
- 2026-11-02
EUVDEUVD-2016-10739
The verify_certificate function in lib/vtls/schannel.c in libcurl 7.30.0 through 7.51.0, when built for Windows CE using the schannel TLS backend, makes it easier for remote attackers to conduct man-in-the-middle attacks via a crafted wildcard SAN in a server certificate, as demonstrated by "*.com."
- Record
EUVD-2016-10739- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-j357-mfhx-p456
The verify_certificate function in lib/vtls/schannel.c in libcurl 7.30.0 through 7.51.0, when...
The verify_certificate function in lib/vtls/schannel.c in libcurl 7.30.0 through 7.51.0, when built for Windows CE using the schannel TLS backend, makes it easier for remote attackers to conduct man-in-the-middle attacks via a crafted wildcard SAN in a server certificate, as demonstrated by "*.com."
- Record
GHSA-j357-mfhx-p456- CVSS 3.0
- 8.1 High
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-295
- Updated
- 2026-11-02
NVD
The verify_certificate function in lib/vtls/schannel.c in libcurl 7.30.0 through 7.51.0, when built for Windows CE using the schannel TLS backend, makes it easier for remote attackers to conduct man-in-the-middle attacks via a crafted wildcard SAN in a server certificate, as demonstrated by "*.com."
- Record
CVE-2016-9952- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 3.0
- 8.1 High
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 6.8 Medium
AV:N/AC:M/Au:N/C:P/I:P/A:P - Weakness
- CWE-295
- Updated
- 2026-11-02
OSVALPINE-CVE-2016-9952
The verify_certificate function in lib/vtls/schannel.c in libcurl 7.30.0 through 7.51.0, when built for Windows CE using the schannel TLS backend, makes it easier for remote attackers to conduct man-in-the-middle attacks via a crafted wildcard SAN in a server certificate, as demonstrated by "*.com."
- Record
ALPINE-CVE-2016-9952- CVSS 3.0
- 8.1 High
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVBELL-CVE-2016-9952
CVE-2016-9952 does not affect BellSoft software
- Record
BELL-CVE-2016-9952- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSV
The verify_certificate function in lib/vtls/schannel.c in libcurl 7.30.0 through 7.51.0, when built for Windows CE using the schannel TLS backend, makes it easier for remote attackers to conduct man-in-the-middle attacks via a crafted wildcard SAN in a server certificate, as demonstrated by "*.com."
- Record
CVE-2016-9952- CVSS 3.0
- 8.1 High
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVCURL-CVE-2016-9952 No score
Win CE Schannel cert wildcard matches too much
curl's TLS server certificate checks are flawed on Windows CE.
This vulnerability occurs in the verify certificate function when comparing a
wildcard certificate name (as returned by the Windows API function
CertGetNameString) to the hostname used to make the connection to the
server.
The vulnerability can be triggered with an overly permissive wildcard SAN in
the server certificate such as a DNS name of *.com. When the function
compares the cert name to the connection hostname, the wildcard character is
removed from the cert name and the connection hostname is checked to see if it
ends with the modified cert name. This means a hostname of example.com would
match a DNS SAN of *.com, among other variations. This approach violates
recommendations in RFC 6125 and could lead to MITM attacks.
- Record
CURL-CVE-2016-9952- Updated
- 2026-11-02
Affected products
Affected packages
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2016-9952 is a high vulnerability (CVSS 8.1) in Haxx Curl, published December 21, 2016. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.28%, the 70th percentile. Fixed in curl 7.52.1-r0.