CVE-2017-3738

MEDIUMCVSS 5.9/10EPSS 13.41%

Last modified

CVE-2017-3738 is a medium-severity vulnerability rated 5.9/10 on the CVSS scale. There is an overflow bug in the AVX2 Montgomery multiplication procedure used in exponentiation with 1024-bit moduli. No EC algorithms are affected. EPSS estimates a 13.41% chance of exploitation in the next 30 days.

Description

There is an overflow bug in the AVX2 Montgomery multiplication procedure used in exponentiation with 1024-bit moduli. 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 DH1024 are considered just feasible, 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 significant. However, for an attack on TLS to be meaningful, the server would have to share the DH1024 private key among multiple clients, which is no longer an option since CVE-2016-0701. This only affects processors that support the AVX2 but not ADX extensions like Intel Haswell (4th generation). Note: The impact from this issue is similar to CVE-2017-3736, CVE-2017-3732 and CVE-2015-3193. OpenSSL version 1.0.2-1.0.2m and 1.1.0-1.1.0g are affected. Fixed in OpenSSL 1.0.2n. Due to the low severity of this issue we are not issuing a new release of OpenSSL 1.1.0 at this time. The fix will be included in OpenSSL 1.1.0h when it becomes available. The fix is also available in commit e502cc86d in the OpenSSL git repository.

Metrics

CVSS 3.1
5.9/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS Probability
13.41%

95.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
OpensslOpenssl1.0.2
OpensslOpenssl1.0.2a
OpensslOpenssl1.0.2b
OpensslOpenssl1.0.2c
OpensslOpenssl1.0.2d
OpensslOpenssl1.0.2e
OpensslOpenssl1.0.2f
OpensslOpenssl1.0.2g
OpensslOpenssl1.0.2h
OpensslOpenssl1.0.2i
OpensslOpenssl1.0.2j
OpensslOpenssl1.0.2k
OpensslOpenssl1.0.2l
OpensslOpenssl1.0.2m
OpensslOpenssl1.1.0
OpensslOpenssl1.1.0a
OpensslOpenssl1.1.0b
OpensslOpenssl1.1.0c
OpensslOpenssl1.1.0d
OpensslOpenssl1.1.0e
OpensslOpenssl1.1.0f
OpensslOpenssl1.1.0g
DebianDebian Linux8.0
DebianDebian Linux9.0
NodejsNode.Js>= 4.0.0, <= 4.1.2
NodejsNode.Js>= 4.2.0, < 4.8.7
NodejsNode.Js>= 6.0.0, <= 6.8.1
NodejsNode.Js>= 6.9.0, < 6.12.2
NodejsNode.Js>= 8.0.0, <= 8.8.1
NodejsNode.Js>= 8.9.0, < 8.9.3
NodejsNode.Js>= 9.0.0, < 9.2.1

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2017-3738?
There is an overflow bug in the AVX2 Montgomery multiplication procedure used in exponentiation with 1024-bit moduli. 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 DH1024 are considered just feasible, 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 significant. However, for an attack on TLS to be meaningful, the server would have to share the DH1024 private key among multiple clients, which is no longer an option since CVE-2016-0701. This only affects processors that support the AVX2 but not ADX extensions like Intel Haswell (4th generation). Note: The impact from this issue is similar to CVE-2017-3736, CVE-2017-3732 and CVE-2015-3193. OpenSSL version 1.0.2-1.0.2m and 1.1.0-1.1.0g are affected. Fixed in OpenSSL 1.0.2n. Due to the low severity of this issue we are not issuing a new release of OpenSSL 1.1.0 at this time. The fix will be included in OpenSSL 1.1.0h when it becomes available. The fix is also available in commit e502cc86d in the OpenSSL git repository.
How severe is CVE-2017-3738?
CVE-2017-3738 has a CVSS score of 5.9/10 (MEDIUM severity). The EPSS model estimates a 13.41% probability of exploitation in the next 30 days.
How do I fix CVE-2017-3738?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2017-3738?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST