Overview
This week we look at some details of the 90 unique CVEs addressed across the supported Ubuntu releases and more.
This week in Ubuntu Security Updates
[USN-4934-2] Exim vulnerabilities [00:41]
16 CVEs addressed in Trusty ESM (14.04 ESM), Xenial (16.04 LTS)CVE-2021-27216 CVE-2020-28025 CVE-2020-28024 CVE-2020-28022 CVE-2020-28020 CVE-2020-28017 CVE-2020-28016 CVE-2020-28015 CVE-2020-28014 CVE-2020-28013 CVE-2020-28012 CVE-2020-28011 CVE-2020-28009 CVE-2020-28008 CVE-2020-28007 CVE-2020-28026 Episode 114[USN-4937-1] GNOME Autoar vulnerability [01:00]
1 CVEs addressed in Bionic (18.04 LTS), Focal (20.04 LTS), Groovy (20.10)CVE-2021-28650 Directory traversal due to failure to properly handle symlinks (result ofincomplete fix for previous CVE-2020-36241)
[USN-4936-1] Thunderbird vulnerabilities [01:47]
5 CVEs addressed in Focal (20.04 LTS), Groovy (20.10)CVE-2021-29950 CVE-2021-23978 CVE-2021-23973 CVE-2021-23969 CVE-2021-23968 78.8.1If used a PGP key but then a failure occurred, TB would keep thedecrypted key in memory - on Ubuntu we enable Yama ptrace restrictions
(ptrace_scope) - so this means processes can only ptrace their
descendents by default and hence even other user-level processes cannot
dump the memory of another process to say extract this private key
Various other CVEs inherited from Firefox[USN-4938-1] Unbound vulnerabilities [03:21]
13 CVEs addressed in Bionic (18.04 LTS), Focal (20.04 LTS)CVE-2020-28935 CVE-2019-25042 CVE-2019-25041 CVE-2019-25040 CVE-2019-25039 CVE-2019-25038 CVE-2019-25037 CVE-2019-25036 CVE-2019-25035 CVE-2019-25034 CVE-2019-25033 CVE-2019-25032 CVE-2019-25031 Validating, recursive DNS resolverRemote DoS, command injection, RCE, local file overwrite etc[USN-4939-1] WebKitGTK vulnerabilities [03:48]
3 CVEs addressed in Bionic (18.04 LTS), Focal (20.04 LTS), Groovy (20.10)CVE-2021-1871 CVE-2021-1844 CVE-2021-1788 1 logic issue, 2 memory corruption bugs - all leading to possible RCE[USN-4940-1] PyYAML vulnerability [04:12]
1 CVEs addressed in Focal (20.04 LTS), Groovy (20.10)CVE-2020-14343 RCE when processing untrusted YAML - due to incomplete fix for previousCVE-2020-1747 - that CVE not specifically patched in Ubuntu as either the
versions of pyyaml were too old to be affected or were based on upstream
releases that had already patched it
[USN-4941-1] Exiv2 vulnerabilities [04:35]
4 CVEs addressed in Xenial (16.04 LTS), Bionic (18.04 LTS), Focal (20.04 LTS), Groovy (20.10), Hirsute (21.04)CVE-2021-3482 CVE-2021-29470 CVE-2021-29458 CVE-2021-29457 EXIF/IPTC/XMP metadata manipulation toolHeap buffer overflow or OOB read when writing metadata - so not so likelyto be triggered by applications that are just extracting metadata etc
Heap buffer overflow for handling EXIF in JPG images[USN-4942-1] Firefox vulnerability [05:09]
1 CVEs addressed in Bionic (18.04 LTS), Focal (20.04 LTS), Groovy (20.10), Hirsute (21.04)CVE-2021-29952 88.0.1Race condition on destruction of WebRender components -> UAF? -> possible RCE[USN-4943-1] XStream vulnerabilities [05:32]
14 CVEs addressed in Bionic (18.04 LTS), Focal (20.04 LTS), Groovy (20.10), Hirsute (21.04)CVE-2021-21351 CVE-2021-21350 CVE-2021-21349 CVE-2021-21348 CVE-2021-21347 CVE-2021-21346 CVE-2021-21345 CVE-2021-21344 CVE-2021-21343 CVE-2021-21342 CVE-2021-21341 CVE-2020-26259 CVE-2020-26258 CVE-2020-26217 Episode 102 - B+F - corresponding fixes for those 3 CVEs for GAlso a heap of others - denial of service, arbitrary code execution,arbitrary file deletion and server-side forgery attacks
[USN-4944-1] MariaDB vulnerabilities [06:04]
Affecting Bionic (18.04 LTS), Focal (20.04 LTS), Groovy (20.10), Hirsute (21.04)Latest upstream point releases rolling in a large number of security fixes:Ubuntu 18.04 LTS has been updated to MariaDB 10.1.48.Ubuntu 20.04 LTS has been updated to MariaDB 10.3.29.Ubuntu 20.10 has been updated to MariaDB 10.3.29.Ubuntu 21.04 has been updated to MariaDB 10.5.10.Thanks to Otto Kekäläinen from the MariaDB foundation for contributingand preparing these updates
[USN-4945-1] Linux kernel vulnerabilities [06:33]
7 CVEs addressed in Bionic (18.04 LTS), Focal (20.04 LTS)CVE-2021-30002 CVE-2021-29650 CVE-2021-29265 CVE-2021-28660 CVE-2021-28375 CVE-2021-28038 CVE-2020-25639 5.4 (standard kernel for 20.04 LTS, HWE for 18.04 LTS)[USN-4946-1] Linux kernel vulnerabilities
9 CVEs addressed in Trusty ESM (14.04 ESM), Xenial (16.04 LTS), Bionic (18.04 LTS)CVE-2021-30002 CVE-2021-29650 CVE-2021-29265 CVE-2021-29264 CVE-2021-28688 CVE-2021-28038 CVE-2021-26931 CVE-2021-26930 CVE-2021-20292 4.15 (standard kernel for 18.04 LTS, HWE for 16.04 ESM, Azure for 14.04ESM)
[USN-4947-1] Linux kernel (OEM) vulnerabilities
5 CVEs addressed in Focal (20.04 LTS)CVE-2021-30002 CVE-2021-29650 CVE-2021-29646 CVE-2021-28375 CVE-2020-35519 5.6 (OEM for 20.04 LTS)[USN-4948-1] Linux kernel (OEM) vulnerabilities
21 CVEs addressed in Focal (20.04 LTS)CVE-2021-3483 CVE-2021-31916 CVE-2021-29657 CVE-2021-29650 CVE-2021-29649 CVE-2021-29647 CVE-2021-29646 CVE-2021-29266 CVE-2021-29264 CVE-2021-28972 CVE-2021-28971 CVE-2021-28964 CVE-2021-28952 CVE-2021-28951 CVE-2021-28688 CVE-2020-25672 CVE-2020-25671 CVE-2020-25670 CVE-2021-3491 CVE-2021-3490 CVE-2021-3489 5.10 (OEM for 20.04 LTS)3 Pwn2Own vulnerabilitiesRyota Shiga - eBPF ring bufferManfred Paul - eBPF bounds tracking on bitwise operationsBilly Jheng Bing-Jhong - io_uringAll OOB writes + info leaks -> local priv esc + code execution asroot
[USN-4949-1] Linux kernel vulnerabilities
12 CVEs addressed in Focal (20.04 LTS), Groovy (20.10)CVE-2021-29650 CVE-2021-29646 CVE-2021-29266 CVE-2021-29265 CVE-2021-29264 CVE-2021-28375 CVE-2021-26931 CVE-2021-26930 CVE-2020-25639 CVE-2021-3491 CVE-2021-3490 CVE-2021-3489 5.8 (standard kernel for 20.10, HWE for 20.04 ESM, Azure for 14.04ESM)
[USN-4950-1] Linux kernel vulnerabilities
3 CVEs addressed in Hirsute (21.04)CVE-2021-3491 CVE-2021-3490 CVE-2021-3489 5.11Plus CAN ISOTP race condition - discovered by a Norbert Slusarek (highschool student in Germany) - local privilege escalation
Introduced via recent broadcast mode support (normally a CAN socketregisters a particular CAN ID to receive and only gets those frames -
was only in 5.11 kernel so only affected hirsute) - this support has
been removed from the hirsute kernel until a proper fix comes from
upstream
[USN-4951-1] Flatpak vulnerability [10:16]
1 CVEs addressed in Bionic (18.04 LTS), Focal (20.04 LTS), Groovy (20.10)CVE-2021-21381 File forwarding issue which could allow an attacker to get access tofiles that are not normally provided by the permissions granted to an app
Use special tokens in the Exec line of the desktop file for an app couldtrick flatpak runtime into providing access to a file as though this had
been explicitly granted by the user
snapd generates desktop files so less likely to be affected by thissort of issue - less untrusted input in general (but perhaps also less
flexible)
Goings on in Ubuntu Security Community
Hiring [11:47]
Linux Cryptography and Security Engineer
https://canonical.com/careers/2612092/linux-cryptography-and-security-engineer-remoteSecurity Engineer - Ubuntu
https://canonical.com/careers/2925180/security-engineer-ubuntu-remoteGet in contact
#ubuntu-security on the Libera.Chat IRC networkubuntu-hardened mailing listSecurity section on discourse.ubuntu.com@ubuntu_sec on twitter