Bugzilla – Bug 991464
VUL-0: CVE-2016-6489: libnettle: RSA code is vulnerable to cache-timing related attacks
Last modified: 2019-02-03 09:52:36 UTC
Quoting from RH BZ: A cache-related side channel was found, in nettle-RSA code. An attacker could use a specially crafted RSA or DSA data, which could make the SSL/TLS connection suspectible to Man-in-the-Middle attacks: rh#1362016 References: https://bugzilla.redhat.com/show_bug.cgi?id=1362016 http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-6489 http://seclists.org/oss-sec/2016/q3/202 https://git.lysator.liu.se/nettle/nettle/commit/3fe1d6549765ecfb24f0b80b2ed086fdc818bff3
I checked the problem. Based on discussion on mailinglist it has quite some issues/regressions. I would recommend actually waiting for upstream to have fix that really works.
This is now released upstream in 3.3: > This release fixes a couple of bugs, and improves resistance > to side-channel attacks on RSA and DSA private key operations. > [...] > > * RSA and DSA now use side-channel silent modular > exponentiation, to defend against attacks on the private key > from evil processes sharing the same processor cache. This > attack scenario is of particular relevance when running an > HTTPS server on a virtual machine, where you don't know who > you share the cache hardware with. > > (Private key operations on elliptic curves were already > side-channel silent).
List of commits: https://git.lysator.liu.se/nettle/nettle/commit/52b9223126b3f997c00d399166c006ae28669068 https://git.lysator.liu.se/nettle/nettle/commit/c66b5f203861729b7a5f006c6f4368acad878f36 https://git.lysator.liu.se/nettle/nettle/commit/b188d67a4db8fe8e8ec9580fdceba227d7d289bf https://git.lysator.liu.se/nettle/nettle/commit/5eb30d94f6f5f3f0cb9ba9ed24bc52b7376176b6 https://git.lysator.liu.se/nettle/nettle/commit/52b9223126b3f997c00d399166c006ae28669068 https://git.lysator.liu.se/nettle/nettle/commit/544b4047de689519ab3e6ec55b776b95b3e264a9
Created attachment 727154 [details] Patch for SLE-12 Hi, I am the new maintainer of this package. After some research, I have seen that the majority of the changes are in commit [1] that switches from function mpz_powm to mpz_powm_sec. Function mpz_powm_sec handles only odd moduli. As mentioned in [2] and the following messages, there are some other parity checks that must me implemented for this new function to work properly, these are given in commits [3-5]. Note that, commit [3] does not apply in 2.7.1. I have just submitted to SLE-12:Update. Could you please check that the applied patch does not break anything? Codestream Version ------------------------------------------------------------- Factory 3.3 Not affected Leap:42.2:Update 2.7.1 Comes from SUSE:SLE-12:Update Leap:42.1:Update 2.7.1 Comes from SUSE:SLE-12:GA SLE-12:Update 2.7.1 mr#133471 [1] https://git.lysator.liu.se/nettle/nettle/commit/3fe1d6549765ecfb24f0b80b2ed086fdc818bff3 [2] https://lists.lysator.liu.se/pipermail/nettle-bugs/2016/003093.html [3] https://git.lysator.liu.se/nettle/nettle/commit/52b9223126b3f997c00d399166c006ae28669068 [4] https://git.lysator.liu.se/nettle/nettle/commit/5eb30d94f6f5f3f0cb9ba9ed24bc52b7376176b6 [5] https://git.lysator.liu.se/nettle/nettle/commit/c66b5f203861729b7a5f006c6f4368acad878f36
Created attachment 727172 [details] Patch for SLE-12 Updated patch and new maintenance request mr#133484.
SUSE-SU-2017:1481-1: An update that fixes one vulnerability is now available. Category: security (moderate) Bug References: 991464 CVE References: CVE-2016-6489 Sources used: SUSE Linux Enterprise Software Development Kit 12-SP2 (src): libnettle-2.7.1-12.1 SUSE Linux Enterprise Server for Raspberry Pi 12-SP2 (src): libnettle-2.7.1-12.1 SUSE Linux Enterprise Server 12-SP2 (src): libnettle-2.7.1-12.1 SUSE Linux Enterprise Desktop 12-SP2 (src): libnettle-2.7.1-12.1
openSUSE-SU-2017:1533-1: An update that fixes one vulnerability is now available. Category: security (moderate) Bug References: 991464 CVE References: CVE-2016-6489 Sources used: openSUSE Leap 42.2 (src): libnettle-2.7.1-10.3.1
released
This is an autogenerated message for OBS integration: This bug (991464) was mentioned in https://build.opensuse.org/request/show/670843 15.1 / libnettle