Overview
SRBDS aka CrossTalk, the latest Intel speculative execution attack, is the
big news this week in security updates for Ubuntu, as well as fixes for
GnuTLS, Firefox and more, plus Alex and Joe talk about using STRIDE for
threat modelling of software products.
This week in Ubuntu Security Updates
[USN-4381-2] Django vulnerabilities [01:00]
2 CVEs addressed in Trusty ESM (14.04 ESM)CVE-2020-13596 CVE-2020-13254 Episode 77[USN-4382-1] FreeRDP vulnerabilities [01:28]
14 CVEs addressed in Xenial (16.04 LTS)CVE-2020-13398 CVE-2020-13397 CVE-2020-13396 CVE-2020-11526 CVE-2020-11525 CVE-2020-11523 CVE-2020-11522 CVE-2020-11521 CVE-2020-11058 CVE-2020-11049 CVE-2020-11048 CVE-2020-11046 CVE-2020-11045 CVE-2020-11042 Episode 77 covered a similar update for FreeRDP2 in 18.04 LTS, 19.10, 20.04 LTSThis is the corresponding update for FreeRDP 1 in 16.04 LTS[USN-4383-1] Firefox vulnerabilities [02:09]
8 CVEs addressed in Xenial (16.04 LTS), Bionic (18.04 LTS), Eoan (19.10), Focal (20.04 LTS)CVE-2020-12399 CVE-2020-12411 CVE-2020-12410 CVE-2020-12409 CVE-2020-12408 CVE-2020-12407 CVE-2020-12406 CVE-2020-12405 77.0.1[USN-4384-1] GnuTLS vulnerability [02:54]
1 CVEs addressed in Eoan (19.10), Focal (20.04 LTS)CVE-2020-13777 Rare Friday update - high priority GnuTLS vulnerability - would use anall-zero key for encrypting TLS session ticket
TLS1.3 -> enables a middleperson attack against resumed sessionsTLS1.2 -> enables passive decryption of traffic to/from servers when theclient supports session tickets
[USN-4386-1] libjpeg-turbo vulnerability [04:19]
1 CVEs addressed in Precise ESM (12.04 ESM), Trusty ESM (14.04 ESM), Xenial (16.04 LTS), Bionic (18.04 LTS), Eoan (19.10), Focal (20.04 LTS)CVE-2020-13790 Heap buffer over-read via crafted PPM file -> info disclosure / crash[USN-4385-1] Intel Microcode vulnerabilities [04:49]
3 CVEs addressed in Trusty ESM (14.04 ESM), Xenial (16.04 LTS), Bionic (18.04 LTS), Eoan (19.10), Focal (20.04 LTS)CVE-2020-0549 CVE-2020-0548 CVE-2020-0543 Latest Intel microarchitectural cache side-channel vulnerabilities - L1Dcache, vector registers, special registers
https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/SRBDSSpecial register buffer data sampling (SRBDS) -> RDRAND, RDSEED etc ->aka CrossTalk -> micro-arch buffer is shared across cores so old values
could be read by other processors
microcode clears buffers -> performance decrease for RDRAND etc as aresult -> kernel update contains support for a kernel command-line arg to
disable this mitigation
[USN-4387-1] Linux kernel vulnerabilities [07:25]
5 CVEs addressed in Bionic (18.04 LTS), Eoan (19.10)CVE-2020-12659 CVE-2020-12464 CVE-2020-12114 CVE-2020-0543 CVE-2020-0067 5.3Kernel command-line option to disable SRBDS mitigationF2FS bounds check fail on xattrs -> OOB read -> info leakUSB scatter-gather UAF -> malicious USB device -> crash / RCEXDP socket fail to validate userspace metadata -> OOB write -> requiresCAP_NET_ADMIN
[USN-4388-1] Linux kernel vulnerabilities [08:40]
6 CVEs addressed in Bionic (18.04 LTS)CVE-2020-1749 CVE-2020-12659 CVE-2020-12464 CVE-2020-12114 CVE-2020-0543 CVE-2020-0067 5.0 gke & oem[USN-4389-1] Linux kernel vulnerabilities [08:54]
6 CVEs addressed in Focal (20.04 LTS)CVE-2020-10751 CVE-2020-12659 CVE-2020-12464 CVE-2020-12114 CVE-2020-0543 CVE-2020-0067 5.4[USN-4390-1] Linux kernel vulnerabilities [09:02]
6 CVEs addressed in Trusty ESM (14.04 ESM), Xenial (16.04 LTS), Bionic (18.04 LTS)CVE-2020-10751 CVE-2020-1749 CVE-2020-12464 CVE-2020-12114 CVE-2020-0543 CVE-2020-0067 4.15 (14.04 ESM azure, 16.04 LTS - hwe, 18.04 LTSall)
As above + IPsec fail to encrypt IPv6 in some conditions -> info leak[USN-4391-1] Linux kernel vulnerabilities [09:35]
8 CVEs addressed in Trusty ESM (14.04 ESM), Xenial (16.04 LTS)CVE-2020-10751 CVE-2020-1749 CVE-2020-12826 CVE-2020-12769 CVE-2020-12464 CVE-2020-12114 CVE-2020-0543 CVE-2019-19319 4.4[USN-4392-1] Linux kernel vulnerabilities [09:46]
3 CVEs addressed in Precise ESM (12.04 ESM), Trusty ESM (14.04 ESM)CVE-2020-12114 CVE-2020-0543 CVE-2020-12654 3.13[USN-4393-1] Linux kernel vulnerabilities [09:46]
2 CVEs addressed in Precise ESM (12.04 ESM)CVE-2020-0543 CVE-2020-12654 3.2Goings on in Ubuntu Security Community
Joe and Alex discuss Threat Modelling via STRIDE [10:12]
https://en.wikipedia.org/wiki/STRIDE_(security)https://threatmodelingbook.com/Get in contact
#ubuntu-security on the Libera.Chat IRC networkubuntu-hardened mailing listSecurity section on discourse.ubuntu.com@ubuntu_sec on twitter