How severe is CVE-2017-3733?

CVE-2017-3733 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2017-3733 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 13% (96th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-3733?

CVE-2017-3733 primarily affects Openssl. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2017-3733?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2017-3733 published?

CVE-2017-3733 was published on 2017-05-04 and last updated on 2026-06-17.

CVE-2017-3733

CVE-2017-3733 is a high-severity vulnerability in Openssl with a CVSS 3.x base score of 7.5. Its EPSS exploit-prediction score of 13% places it in the 96th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-20.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 13% (96th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Openssl
Published: 2017-05-04
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2017-3733?: 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.
How severe is CVE-2017-3733?: CVE-2017-3733 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2017-3733 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 13% (96th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-3733?: CVE-2017-3733 primarily affects Openssl. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2017-3733?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2017-3733 published?: CVE-2017-3733 was published on 2017-05-04 and last updated on 2026-06-17.

References

Affected products (7)

cpe:2.3:a:openssl:openssl:1.1.0:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.1.0a:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.1.0b:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.1.0c:*:*:*:*:*:*:*
cpe:2.3:a:openssl:openssl:1.1.0d:*:*:*:*:*:*:*
cpe:2.3:a:hp:operations_agent:11.14:*:*:*:*:*:*:*
cpe:2.3:a:hp:operations_agent:11.15:*:*:*:*:*:*:*

More vulnerabilities in Openssl

CVE-2009-3245 — Critical (CVSS 10.0): OpenSSL before 0.9.8m does not check for a NULL return value from bn_wexpand function calls in (1) crypto/bn/bn_div.c,…
CVE-2006-3738 — Critical (CVSS 10.0): Buffer overflow in the SSL_get_shared_ciphers function in OpenSSL 0.9.7 before 0.9.7l, 0.9.8 before 0.9.8d, and earlier…
CVE-2026-31789 — Critical (CVSS 9.8): Issue summary: Converting an excessively large OCTET STRING value to a hexadecimal string leads to a heap buffer…
CVE-2022-2274 — Critical (CVSS 9.8): The OpenSSL 3.0.4 release introduced a serious bug in the RSA implementation for X86_64 CPUs supporting the AVX512IFMA…
CVE-2021-3711 — Critical (CVSS 9.8): In order to decrypt SM2 encrypted data an application is expected to call the API function EVP_PKEY_decrypt().…
CVE-2016-6309 — Critical (CVSS 9.8): statem/statem.c in OpenSSL 1.1.0a does not consider memory-block movement after a realloc call, which allows remote…

All CVEs affecting Openssl →

Other CWE-20 (Improper Input Validation) vulnerabilities

CVE-2026-48316 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48281 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48277 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48055 — Critical (CVSS 10.0): Streambert is a cross-platform Electron Desktop App to stream and download any video media. In versions 2.4.0 and…
CVE-2026-34910 — Critical (CVSS 10.0): A malicious actor with access to the network could exploit an Improper Input Validation vulnerability found in UniFi OS…
CVE-2026-33587 — Critical (CVSS 10.0): Lack of user input sanitisation in Open Notebook v1.8.3 allows the application user to execute Python code (and…

Browse all CWE-20 (Improper Input Validation) vulnerabilities →