CVE-2017-3733 | Encrypt-Then-Mac renegotiation crash

During a renegotiation handshake if the Encrypt-Then-Mac extension is negotiated where it was not in the original handshake (or vice-versa) then this can cause OpenSSL 1.1.0 before 1.1.0e to crash (dependent on ciphersuite). Both clients and servers are affected.

Published: 2017-05-04 Last update: 2026-05-13 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2017-3733 is rated High Risk (68.5/100): CVSS High severity, with high exploitation likelihood (EPSS 12.64%, 96th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +9.54% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2017-3733

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 3.10% 12.64% +9.54%
2 2026-03-23 3.31% 3.10% -0.22%
3 2026-03-22 — 3.31% —

Full EPSS history (25 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2017-3733

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2017-3733

OS Trackers for CVE-2017-3733

vendor priority summary link
debian not yet assigned CVE-2017-3733 not yet assigned priority: Debian including 1 source packages (openssl), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2017-3733
redhat high — https://access.redhat.com/security/cve/CVE-2017-3733
ubuntu high CVE-2017-3733 high priority: Ubuntu including 2 source packages (openssl, openssl098), 10 status rows across 5 suites (precise, trusty, upstream, xenial, yakkety): not-affected 5, DNE 3, needs-triage 2. https://ubuntu.com/security/CVE-2017-3733

Affected software / configurations for CVE-2017-3733

Vendor Product Version Raw CPE
openssl openssl 1.1.0 cpe:2.3:a:openssl:openssl:1.1.0:*:*:*:*:*:*:*
openssl openssl 1.1.0a cpe:2.3:a:openssl:openssl:1.1.0a:*:*:*:*:*:*:*
openssl openssl 1.1.0b cpe:2.3:a:openssl:openssl:1.1.0b:*:*:*:*:*:*:*
openssl openssl 1.1.0c cpe:2.3:a:openssl:openssl:1.1.0c:*:*:*:*:*:*:*
openssl openssl 1.1.0d cpe:2.3:a:openssl:openssl:1.1.0d:*:*:*:*:*:*:*
hp operations_agent 11.14 cpe:2.3:a:hp:operations_agent:11.14:*:*:*:*:*:*:*
hp operations_agent 11.15 cpe:2.3:a:hp:operations_agent:11.15:*:*:*:*:*:*:*

References for CVE-2017-3733

cvelogic Threat Intelligence