CVE-2017-3737
MediumOpenSSL 1.0.2 (starting from version 1.0.2b) introduced an "error state" mechanism.
Published Dec 7, 2017 · Updated Aug 4, 2026 · Also known as ALPINE-CVE-2017-3737, DEBIAN-CVE-2017-3737, DSA-4065-1, SUSE-SU-2017:3343-1, UBUNTU-CVE-2017-3737, USN-3512-1
Key Facts
Patch immediately- CVE-2017-3737 is a medium-severity vulnerability (CVSS 5.9 v3.1) affecting OpenSSL, Debian Linux, openssl1.0 (debian) and 22 more products.
- It is not listed in any known-exploited vulnerabilities catalog. No public exploit code is known.
- EPSS estimates a 79% probability of exploitation in the next 30 days.
- Fixed versions are available, including jbcs-httpd24-apache-commons-daemon 0:1.1.0-1.redhat_2.1.jbcs.el6, jbcs-httpd24-apache-commons-daemon 0:1.1.0-1.redhat_2.1.jbcs.el7, jbcs-httpd24-apache-commons-daemon-jsvc 1:1.1.0-1.redhat_2.jbcs.el6.
- Brandefense priority: patch immediately, because it is very likely to be exploited soon.
CVSS v3.1
5.9
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS (30-day exploit likelihood)
79%
Higher than 99.5% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
None known
Get the full CVE-2017-3737 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
OpenSSL 1.0.2 (starting from version 1.0.2b) introduced an "error state" mechanism. The intent was that if a fatal error occurred during a handshake then OpenSSL would move into the error state and would immediately fail if you attempted to continue the handshake. This works as designed for the explicit handshake functions (SSL_do_handshake(), SSL_accept() and SSL_connect()), however due to a bug it does not work correctly if SSL_read() or SSL_write() is called directly. In that scenario, if the handshake fails then a fatal error will be returned in the initial function call. If SSL_read()/SSL_write() is subsequently called by the application for the same SSL object then it will succeed and the data is passed without being decrypted/encrypted directly from the SSL/TLS record layer. In order to exploit this issue an application bug would have to be present that resulted in a call to SSL_read()/SSL_write() being issued after having already received a fatal error. OpenSSL version 1.0.2b-1.0.2m are affected. Fixed in OpenSSL 1.0.2n. OpenSSL 1.1.0 is not affected.
Affected Products
212 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| OpenSSLOpenssl | 1.0.2b, 1.0.2c, 1.0.2d, 1.0.2e, 1.0.2f, 1.0.2g, 1.0.2h, 1.0.2i | 1.0.2n-r0 |
| Debian LinuxDebian | 9.0 | n/a |
| openssl1.0debian | See advisory | 1.0.2l-2+deb9u2 |
| rootio-opensslrootio | See advisory | 1.1.0b-2 |
| openssl-develamazon | See advisory | 1:1.0.2k-12.109.amzn1 |
Patched Releases
jbcs-httpd24-apache-commons-daemon
0:1.1.0-1.redhat_2.1.jbcs.el6, 0:1.1.0-1.redhat_2.1.jbcs.el7
jbcs-httpd24-apache-commons-daemon-jsvc
1:1.1.0-1.redhat_2.jbcs.el6, 1:1.1.0-1.redhat_2.jbcs.el7
jbcs-httpd24-apr
0:1.6.3-14.jbcs.el6, 0:1.6.3-14.jbcs.el7
jbcs-httpd24-apr-util
0:1.6.1-9.jbcs.el6, 0:1.6.1-9.jbcs.el7
jbcs-httpd24-httpd
0:2.4.29-17.jbcs.el6, 0:2.4.29-17.jbcs.el7
jbcs-httpd24-mod_auth_kerb
0:5.4-36.jbcs.el6, 0:5.4-36.jbcs.el7
jbcs-httpd24-mod_bmx
0:0.9.6-17.GA.jbcs.el6, 0:0.9.6-17.GA.jbcs.el7
jbcs-httpd24-mod_cluster-native
0:1.3.8-1.Final_redhat_2.jbcs.el6, 0:1.3.8-1.Final_redhat_2.jbcs.el7
jbcs-httpd24-mod_jk
0:1.2.43-1.redhat_1.jbcs.el6, 0:1.2.43-1.redhat_1.jbcs.el7
jbcs-httpd24-mod_rt
0:2.4.1-19.GA.jbcs.el6, 0:2.4.1-19.GA.jbcs.el7
jbcs-httpd24-mod_security
0:2.9.1-23.GA.jbcs.el6, 0:2.9.1-23.GA.jbcs.el7
jbcs-httpd24-nghttp2
0:1.29.0-8.jbcs.el6, 0:1.29.0-8.jbcs.el7
jbcs-httpd24-openssl
1:1.0.2n-11.jbcs.el6, 1:1.0.2n-11.jbcs.el7
libmysql56client_r18
5.6.39-33.1
libmysql56client_r18-32bit
5.6.39-33.1
libmysql56client18
5.6.39-33.1
libmysql56client18-32bit
5.6.39-33.1
libopenssl-1_0_0-devel
1.0.2u-6.2
libopenssl-1_0_0-devel-32bit
1.0.2u-6.2
libopenssl-devel
1.0.2j-16.1, 1.0.2j-60.20.2
libopenssl-devel-32bit
1.0.2j-16.1
libopenssl1_0_0
1.0.2j-16.1, 1.0.2j-60.20.2, 1.0.2u-6.2
libopenssl1_0_0-32bit
1.0.2j-16.1, 1.0.2j-60.20.2, 1.0.2u-6.2
libopenssl1_0_0-hmac
1.0.2j-16.1, 1.0.2j-60.20.2, 1.0.2u-6.2
libopenssl1_0_0-hmac-32bit
1.0.2j-16.1, 1.0.2j-60.20.2, 1.0.2u-6.2
Timeline
Publicly disclosed
Dec 7, 2017
Last updated
Aug 4, 2026
Weakness Type
- CWE-125 Out-of-bounds Read
- CWE-391 Unchecked Error Condition
- CWE-787 Out-of-bounds Write
References
- advisoryRHSA-2018:0998
- advisoryRHSA-2018:2185
- advisoryRHSA-2018:2186
- advisoryRHSA-2018:2187
- advisoryhttps://bugzilla.suse.com/1071905
FAQ
Common Questions.
OpenSSL 1.0.2 (starting from version 1.0.2b) introduced an "error state" mechanism.
Affected: OpenSSL versions 1.0.2b, 1.0.2c, 1.0.2d, 1.0.2e, 1.0.2f, 1.0.2g, 1.0.2h, 1.0.2i; Debian Linux versions 9.0; openssl1.0 (debian), among others. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
Fixed versions are available, including jbcs-httpd24-apache-commons-daemon 0:1.1.0-1.redhat_2.1.jbcs.el6, jbcs-httpd24-apache-commons-daemon 0:1.1.0-1.redhat_2.1.jbcs.el7, jbcs-httpd24-apache-commons-daemon-jsvc 1:1.1.0-1.redhat_2.jbcs.el6.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.
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