Mozilla: Certificate verification bypass through the HTTP/2 Alt-Svc header (MFSA 2015-44)
Published Apr 8, 2015
4.3
MEDIUMCVSS 2.0
EPSS 1.17%
Description
The HTTP Alternative Services feature in Mozilla Firefox before 37.0.1 allows man-in-the-middle attackers to bypass an intended X.509 certificate-verification step for an SSL server by specifying that server in the uri-host field of an Alt-Svc HTTP/2 response header.
Affected products
No data.
Configuration 1
- 12.04
- 14.04
- 14.10
No data.
Red Hat Enterprise Linux 5
firefox
Not affected
Red Hat Enterprise Linux 5
thunderbird
Not affected
Red Hat Enterprise Linux 6
firefox
Not affected
Red Hat Enterprise Linux 6
thunderbird
Not affected
Red Hat Enterprise Linux 7
firefox
Not affected
Red Hat Enterprise Linux 7
thunderbird
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 5 | firefox | Not affected | n/a |
| Red Hat Enterprise Linux 5 | thunderbird | Not affected | n/a |
| Red Hat Enterprise Linux 6 | firefox | Not affected | n/a |
| Red Hat Enterprise Linux 6 | thunderbird | Not affected | n/a |
| Red Hat Enterprise Linux 7 | firefox | Not affected | n/a |
| Red Hat Enterprise Linux 7 | thunderbird | Not affected | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
This issue does not affect the version of firefox and thunderbird as shipped with Red Hat Enterprise Linux 5, 6 and 7.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
No CVSS v3.0 score for this CVE.
AV:N/AC:M/Au:N/C:N/I:P/A:N
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (10 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 1.17% (0.01174) | 66.35th | v5 (v2026.06.15) |
| Jun 15, 2026 | 1.17% (0.01174) | 63.31th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.12% (0.00124) | 29.09th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.14% (0.00145) | 51.89th | v3 (v2023.03.01) |
| Jun 15, 2024 | 0.15% (0.00147) | 50.84th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.15% (0.00147) | 48.83th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.11% (0.01108) | 55.18th | v2 (v2022.01.01) |
| Sep 17, 2022 | 1.11% (0.01108) | 53.57th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.11% (0.01108) | 51.54th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.11% (0.01108) | 29.61th | v2 (v2022.01.01) |
References (11)
- http://lists.opensuse.org/opensuse-security-announce/2015-04/msg00003.html vendor-advisoryx_refsource_SUSE
- http://www.mozilla.org/security/announce/2015/mfsa2015-44.html x_refsource_CONFIRMVendor Advisory
- http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html x_refsource_CONFIRM
- http://www.securitytracker.com/id/1032030 vdb-entryx_refsource_SECTRACK
- http://www.ubuntu.com/usn/USN-2557-1 vendor-advisoryx_refsource_UBUNTU
- https://access.redhat.com/security/cve/CVE-2015-0799 Vendor Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1148328 x_refsource_CONFIRM
- https://bugzilla.redhat.com/show_bug.cgi?id=1208731 Issue Tracking
- https://nvd.nist.gov/vuln/detail/CVE-2015-0799
- https://security.gentoo.org/glsa/201512-10 vendor-advisoryx_refsource_GENTOO
- https://www.cve.org/CVERecord?id=CVE-2015-0799
| Link | Providers | Tags |
|---|---|---|
| http://lists.opensuse.org/opensuse-security-announce/2015-04/msg00003.html | vendor-advisoryx_refsource_SUSE | |
| http://www.mozilla.org/security/announce/2015/mfsa2015-44.html | x_refsource_CONFIRMVendor Advisory | |
| http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html | x_refsource_CONFIRM | |
| http://www.securitytracker.com/id/1032030 | vdb-entryx_refsource_SECTRACK | |
| http://www.ubuntu.com/usn/USN-2557-1 | vendor-advisoryx_refsource_UBUNTU | |
| https://access.redhat.com/security/cve/CVE-2015-0799 | Vendor Advisory | |
| https://bugzilla.mozilla.org/show_bug.cgi?id=1148328 | x_refsource_CONFIRM | |
| https://bugzilla.redhat.com/show_bug.cgi?id=1208731 | Issue Tracking | |
| https://nvd.nist.gov/vuln/detail/CVE-2015-0799 | ||
| https://security.gentoo.org/glsa/201512-10 | vendor-advisoryx_refsource_GENTOO | |
| https://www.cve.org/CVERecord?id=CVE-2015-0799 |
Change history (0)
No recorded changes yet.