Information disclosure in Openssl
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.
Vulnerability class: Information Disclosure
EPSS: 0.101 (95.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
Affected products
- Openssl
- Openssl Software Foundation — versions 1.1.0 - 1.1.0f, 1.0.2 - 1.0.2l
Weakness classification (CWE)
Public proof-of-concept exploits
References
- openssl-security@openssl.org (x_refsource_CONFIRM, Third Party Advisory, Issue Tracking)
- openssl-security@openssl.org (x_refsource_REDHAT, vendor-advisory, Third Party Advisory)
- openssl-security@openssl.org (Third Party Advisory, x_refsource_MISC)
- openssl-security@openssl.org (x_refsource_REDHAT, vendor-advisory, Third Party Advisory)
- openssl-security@openssl.org (x_refsource_CONFIRM, Patch, Third Party Advisory)
- openssl-security@openssl.org (x_refsource_CONFIRM, Patch, Third Party Advisory)
- openssl-security@openssl.org (x_refsource_REDHAT, vendor-advisory, Third Party Advisory)
- openssl-security@openssl.org (x_refsource_CONFIRM)
- openssl-security@openssl.org (vendor-advisory, Third Party Advisory, Issue Tracking, x_refsource_DEBIAN)
- openssl-security@openssl.org (vendor-advisory, Third Party Advisory, x_refsource_GENTOO)
Frequently asked questions
- What is CVE-2017-3736?
- CVE-2017-3736 is a medium-severity vulnerability in Openssl, classified under Information Disclosure. CVSS score: 6.5/10. Published 2017-11-02.
- How severe is CVE-2017-3736?
- Medium severity. CVSS v3 base score is 6.5 out of 10.
- Is CVE-2017-3736 known to be exploited?
- 4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.