Vulnerability in Apache HTTP Server
CVE-2016-4979
The Apache HTTP Server 2.4.18 through 2.4.20, when mod_http2 and mod_ssl are enabled, does not properly recognize the "SSLVerifyClient require" directive for HTTP/2 request authorization, which allows remote attackers to bypass intended access restrictions by leveraging the ability to send multiple requests over a single connection and aborting a renegotiation.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.188 (97.2th percentile), scored .
Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 97th percentile — 97.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.188 · newest: 0.188 · change: 0.000
Affected products
- Apache HTTP Server — versions 2.4.18, 2.4.19, 2.4.20
Weakness classification (CWE)
Public proof-of-concept exploits
References
- access.redhat.com/errata/RHSA-2016:1420 (vendor-advisory)
- httpd.apache.org/security/vulnerabilities_24.html (Patch, Vendor Advisory)
- security.gentoo.org/glsa/201610-02 (vendor-advisory)
- seclists.org/fulldisclosure/2016/Jul/11 (mailing-list)
- www.oracle.com/technetwork/security-advisory/cpuoct2016-2881722.html
- www.apache.org/dist/httpd/CHANGES_2.4
- www.securityfocus.com/bid/91566 (vdb-entry)
- www.oracle.com/technetwork/topics/security/bulletinoct2016-3090566.html
- www.securitytracker.com/id/1036225 (vdb-entry)
- www.openwall.com/lists/oss-security/2016/07/05/5 (mailing-list)
Frequently asked questions
- What is CVE-2016-4979?
- CVE-2016-4979 is a high-severity vulnerability in Apache HTTP Server, classified under Improper Access Control. CVSS score: 7.5/10. Published 2016-07-06.
- How severe is CVE-2016-4979?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2016-4979 known to be exploited?
- 7 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.