SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2017-3736

The amount of resources required for such an attack would be very significant and likely only accessible to a limited number of attackers.

MEDIUM 6.5EPSS 10.1%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 10.1%, higher than 95% of all known CVEs. Patch or mitigate before the next change window.

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.

CVSS 3.0
6.5 MEDIUMCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
EPSS
10.13% probability · 95th percentile
CISA KEV
Not listed
Weakness
CWE-200
Affected
openssl/openssl
Source
openssl-security@openssl.org

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.