CVE-2017-3738

Name	CVE-2017-3738
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.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DSA-4065-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
openssl (PTS)	jessie, jessie (lts)	1.0.1t-1+deb8u21	fixed
	stretch (security)	1.1.0l-1~deb9u6	fixed
	stretch (lts), stretch	1.1.0l-1~deb9u9	fixed
	buster (security), buster, buster (lts)	1.1.1n-0+deb10u6	fixed
	bullseye	1.1.1w-0+deb11u1	fixed
	bullseye (security)	1.1.1w-0+deb11u2	fixed
	bookworm	3.0.15-1~deb12u1	fixed
	bookworm (security)	3.0.14-1~deb12u2	fixed
	sid, trixie	3.3.2-2	fixed
openssl1.0 (PTS)	stretch (security)	1.0.2u-1~deb9u7	fixed
	stretch (lts), stretch	1.0.2u-1~deb9u9	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin
openssl	source	wheezy	(not affected)
openssl	source	jessie	(not affected)
openssl	source	stretch	1.1.0f-3+deb9u2
openssl	source	(unstable)	1.1.0h-1	low
openssl1.0	source	stretch	1.0.2l-2+deb9u2		DSA-4065-1
openssl1.0	source	(unstable)	1.0.2n-1	low

Notes

[jessie] - openssl <not-affected> (Vulnerable code not present)
[wheezy] - openssl <not-affected> (Vulnerable code not present)
https://www.openssl.org/news/secadv/20171207.txt
OpenSSL_1_1_0-stable: https://git.openssl.org/?p=openssl.git;a=commit;h=e502cc86df9dafded1694fceb3228ee34d11c11a
OpenSSL_1_0_2-stable: https://git.openssl.org/?p=openssl.git;a=commit;h=ca51bafc1a88d8b8348f5fd97adc5d6ca93f8e76