CVE-2017-3736

CVE-2017-3736 is a medium-severity vulnerability in Openssl with a CVSS 3.x base score of 6.5. Its EPSS exploit-prediction score of 10% places it in the 95th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-200.

Key facts

Description

There is a carry propagating bug in the x86_64 Montgomery squaring procedure in OpenSSL before 1.0.2m and 1.1.0 before 1.1.0g. No EC algorithms are affected. Analysis suggests that attacks against RSA and DSA as a result of this defect would be very difficult to perform and are not believed likely. Attacks against DH are considered just feasible (although very difficult) because most of the work necessary to deduce information about a private key may be performed offline. The amount of resources required for such an attack would be very significant and likely only accessible to a limited number of attackers. An attacker would additionally need online access to an unpatched system using the target private key in a scenario with persistent DH parameters and a private key that is shared between multiple clients. This only affects processors that support the BMI1, BMI2 and ADX extensions like Intel Broadwell (5th generation) and later or AMD Ryzen.

Frequently asked questions

What is CVE-2017-3736?
There is a carry propagating bug in the x86_64 Montgomery squaring procedure in OpenSSL before 1.0.2m and 1.1.0 before 1.1.0g. No EC algorithms are affected. Analysis suggests that attacks against RSA and DSA as a result of this defect would be very difficult to perform and are not believed likely. Attacks against DH are considered just feasible (although very difficult) because most of the work necessary to deduce information about a private key may be performed offline. The amount of resources required for such an attack would be very significant and likely only accessible to a limited number of attackers. An attacker would additionally need online access to an unpatched system using the target private key in a scenario with persistent DH parameters and a private key that is shared between multiple clients. This only affects processors that support the BMI1, BMI2 and ADX extensions like Intel Broadwell (5th generation) and later or AMD Ryzen.
How severe is CVE-2017-3736?
CVE-2017-3736 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2017-3736 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 10% (95th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-3736?
CVE-2017-3736 affects Openssl. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2017-3736?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2017-3736 published?
CVE-2017-3736 was published on 2017-11-02 and last updated on 2026-06-17.

References

Affected products (1)

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Threat intelligence

Threat-intel indicators referencing this CVE: