Overview
Big roundup of security updates from the past 2 weeks including Docker,
ZeroMQ, Squid, Redis and more, plus we talk with Joe McManus about some
recent big fines for companies breaching their GDPR responsibilities and
it’s EOL for Ubuntu 18.10 Cosmic Cuttlefish.
This week in Ubuntu Security Updates
[USN-4047-1] libvirt vulnerabilities
4 CVEs addressed in Xenial, Bionic, Cosmic, DiscoCVE-2019-10168CVE-2019-10167CVE-2019-10166CVE-2019-10161All related - in each case various libvirt APIs were accessible to userswith read-only permissions and allowed them to perform operations which
they should not have access to - in one case providing an ability to
escalate privileges to root on the host - since would allow to execute
arbitrary binaries with elevated permissions.
By default, libvirt is constrained by AppArmor in Ubuntu which providessome isolation to help in these cases
[USN-4048-1] Docker vulnerabilities
2 CVEs addressed in Xenial, Bionic, Cosmic, DiscoCVE-2019-5736CVE-2018-15664Directory traversal via crafted symlink exchange (TOCTOU) via docker cpcommand - docker cp can be used to copy files between host and
container - to do this safely, need to resolve paths as though were in
the container - so tries to check a path by resolving symlinks, and then
later use it if validates - but race exists where can then modify a
component in the path via symlink after the check but before the
copy, so can then overwrite arbitrary files on the host -> privilege
escalation
runc component in docker could allow a container to overwrite the runcbinary on the host -> privilege escalation (and container escape) to the
runc context on the host
https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/runC[USN-4049-1, USN-4049-2] GLib vulnerability
1 CVEs addressed in Precise ESM, Trusty ESM, Xenial, Bionic, CosmicCVE-2019-13012Similar to CVE-2019-12450 (Episode 36) - in this case, directories andfiles would get created with default permisssions, not restrictive
permissions, when using the keyfile gsettings backend - could expose
settings or allow other users to modify settings etc.
[USN-4050-1] ZeroMQ vulnerability
1 CVEs addressed in Xenial, Bionic, Cosmic, DiscoCVE-2019-13132Stack buffer overflow when using CURVE encryption/authentication -> RCE[USN-4051-1, USN-4051-2] Apport vulnerability
1 CVEs addressed in Trusty ESM, Xenial, Bionic, Cosmic, DiscoCVE-2019-7307Reported by Kevin Backhouse of Semmle Security Research TeamTOCTOU when processing a users own ignore configuration fileApport runs as root, but would check permission to file via access()system call - which uses the real processes’ UID / GID - so is safe as a
permission check - BUT would then go and open the file - so in the
meantime this could be replaced by a symlink to say a root owned file
which could then get included in the resulting crash report
Fix is to seteuid() as the desired user to set effective UID to thenactually open the file before restoring euid to root - so this does both
the equivalent of the access and open in 1 call avoiding to TOCTOU
[USN-4052-1] Whoopsie vulnerability
1 CVEs addressed in Xenial, Bionic, Cosmic, DiscoCVE-2019-11476Reported by Kevin Backhouse of Semmle Security Research TeamInteger overflow when processing crash dump - when parsing the crashdump, if it contained an artificially large value in the dump file, would
overflow length calculation, then would result in a heap-buffer OOB write
-> crash, DoS OR code-execution as whoopsie process.
When coupled with previous Apport bug could allow an arbitrary user toread any file on the system by first embedding it in a crash dump via
Apport and then triggering Whoopsie to process it and expose the via
arbitrary code execution
[USN-4053-1] GVfs vulnerabilities
4 CVEs addressed in Xenial, Bionic, Cosmic, DiscoCVE-2019-12795CVE-2019-12449CVE-2019-12448CVE-2019-12447gvfs private server socket did not configure any authorisation - so anyuser could possible connect to it and issue API calls -> possible code
exection as another user
files created / moved by admin backend could end up with wrong fileownership - admin backend allows to access root files as normal user (via
admin authorisation) - so can copy files as a user to root’s home which
then are still owned by the original user
[USN-4054-1] Firefox vulnerabilities
21 CVEs addressed in Xenial, Bionic, Cosmic, DiscoCVE-2019-11730CVE-2019-11729CVE-2019-11728CVE-2019-11727CVE-2019-11725CVE-2019-11724CVE-2019-11723CVE-2019-11721CVE-2019-11720CVE-2019-11719CVE-2019-11718CVE-2019-11717CVE-2019-11716CVE-2019-11715CVE-2019-11714CVE-2019-11713CVE-2019-11712CVE-2019-11711CVE-2019-11710CVE-2019-11709CVE-2019-9811Upstream release 68.0[USN-4064-1] Thunderbird vulnerabilities
10 CVEs addressed in Xenial, Bionic, Cosmic, DiscoCVE-2019-11730CVE-2019-11729CVE-2019-11719CVE-2019-11717CVE-2019-11715CVE-2019-11713CVE-2019-11712CVE-2019-11711CVE-2019-11709CVE-2019-9811Upstream release 60.8[USN-4055-1] flightcrew vulnerabilities
3 CVEs addressed in Xenial, Bionic, Cosmic, DiscoCVE-2019-13453CVE-2019-13241CVE-2019-13032Mike Salvatore discovered and coordinated with upstream on fixing these issuesFound 2 through fuzzing, 1 though code-analysis whilst analysing first two vulnerabilites2 fuzzing bugs1 NULL pointer dereference (crash, DoS)1 infinite loop (CPU DoS)1 zip slip - write files outside of working directory when handling zip files (EPUB is a ZIP file)Great write-up on his blog:https://salvatoresecurity.com/fun-with-fuzzers-or-how-i-discovered-three-vulnerabilities-part-1-of-3/https://salvatoresecurity.com/fun-with-fuzzers-how-i-discovered-three-vulnerabilities-part-2-of-3/https://salvatoresecurity.com/fun-with-fuzzers-how-i-discovered-three-vulnerabilities-part-3-of-3/[USN-4056-1] Exiv2 vulnerabilities
7 CVEs addressed in Xenial, Bionic, Cosmic, DiscoCVE-2019-13114CVE-2019-13113CVE-2019-13110CVE-2019-13112CVE-2018-19535CVE-2018-19108CVE-2018-19107Library and CLI toolks to manage image metadataAll DoS - assertion failure / NULL pointer dereference / OOB read /uncontrolled memory allocation / infinite loop
[USN-4057-1] Zipios vulnerability
1 CVEs addressed in Xenial, Bionic, Cosmic, DiscoCVE-2019-13453Same as the flightcrew infinite loop issue since flightcrew contains anembedded copy of zipios
[USN-4058-1] Bash vulnerability
1 CVEs addressed in XenialCVE-2019-9924rbash did not prevent modifying BASH_CMDS so user could execute anycommands as the shell, defeating the purpose of rbash
[USN-4059-1, USN-4059-2] Squid vulnerabilities
2 CVEs addressed in Precise ESM, Xenial, Bionic, DiscoCVE-2019-13345CVE-2018-19132XSS in cachemgr CGI web module, and memory leak in SNMP module[USN-4060-1, USN-4060-2] NSS vulnerabilities
3 CVEs addressed in Precise ESM, Trusty ESM, Xenial, Bionic, DiscoCVE-2019-11729CVE-2019-11727CVE-2019-117193 of the CVEs from the Firefox update (since Firefox contains libnss)Empty public keys could trigger a segfaultPossible to force to sign with wrong signature type with TLS 1.3OOB read when importing a private key with leading NUL bytes -> infodisclosure / crash
[USN-4061-1] Redis vulnerabilities
2 CVEs addressed in Xenial, Bionic, DiscoCVE-2019-10193CVE-2019-101921 stack, and 1 heap based buffer overflows when handling purposelycorrupted hyperloglog data structure
[USN-4062-1] WavPack vulnerabilities
4 CVEs addressed in Bionic, DiscoCVE-2019-1010319CVE-2019-1010318CVE-2019-1010317CVE-2019-10103153 different DoS issues (1 CVE was found to be the same as the other)2 * use of uninitialised variableDivide by zero[USN-4063-1] LibreOffice vulnerabilities
2 CVEs addressed in Xenial, Bionic, DiscoCVE-2019-9849CVE-2019-9848RCE via a malicious document - docs can contain python - and this can beused with the built-in LibreLogo turtle graphics script to execute
bundled python code - so can get RCE via a mouse-over event using
LibreLogo and embedded python
Stealth mode - documents can only fetch resources from ’trusted'locations
Allows to disable the normal remote resource handling in documents tobe a more private mode
BUT bullet graphics not included - so could specify a remote bulletgraphic from a non-trusted location and would still be fetched
[USN-4065-1] Squid vulnerabilities
3 CVEs addressed in Xenial, Bionic, DiscoCVE-2019-12529CVE-2019-12527CVE-2019-125253 different possible crash bugs via memory corruption -> DoS, but alsomaybe RCE…
1 when using digest auth and 2 for basic auth[USN-4066-1] libmspack vulnerability
1 CVEs addressed in Xenial, BionicCVE-2019-1010305Buffer over-read with malicious chm file -> crash, DoSGoings on in Ubuntu Security Community
Discussion with Joe McManus on recent large GDPR fines for Marriot and British Airways
https://thehackernews.com/2019/07/british-airways-breach-gdpr-fine.htmlhttps://threatpost.com/marriott-123m-fine-data-breach/146320/Ubuntu 18.10 (Cosmic Cuttlefish) End-of-Life
Ubuntu 18.10 Cosmic Cuttlefish EOL was on 18th July, 2019https://lists.ubuntu.com/archives/ubuntu-security-announce/2019-July/005021.htmlGet in contact
[email protected]#ubuntu-security on the Libera.Chat IRC network@ubuntu_sec on twitter