Apport race condition in crash report permissions

Time-of-check Time-of-use Race Condition vulnerability on crash report ownership change in Apport allows for a possible privilege escalation opportunity. If fs.protected_symlinks is disabled, this can be exploited between the os.open and os.chown calls when the Apport cron script clears out crash files of size 0. A symlink with the same name as the deleted file can then be created upon which chown will be called, changing the file owner to root. Fixed in versions 2.20.1-0ubuntu2.23, 2.20.9-0ubuntu7.14, 2.20.11-0ubuntu8.8 and 2.20.11-0ubuntu22.

Ubuntu 18.04 Linux kernel i915 incomplete fix for CVE-2019-14615

The fix for the Linux kernel in Ubuntu 18.04 LTS for CVE-2019-14615 ("The Linux kernel did not properly clear data structures on context switches for certain Intel graphics processors.") was discovered to be incomplete, meaning that in versions of the kernel before 4.15.0-91.92, an attacker could use this vulnerability to expose sensitive information.

World writable root owned lock file created in user controllable location

Apport creates a world writable lock file with root ownership in the world writable /var/lock/apport directory. If the apport/ directory does not exist (this is not uncommon as /var/lock is a tmpfs), it will create the directory, otherwise it will simply continue execution using the existing directory. This allows for a symlink attack if an attacker were to create a symlink at /var/lock/apport, changing apport's lock file location. This file could then be used to escalate privileges, for example. Fixed in versions 2.20.1-0ubuntu2.23, 2.20.9-0ubuntu7.14, 2.20.11-0ubuntu8.8 and 2.20.11-0ubuntu22.

OpenSMTPD before 6.6.4 allows remote code execution because of an out-of-bounds read in mta_io in mta_session.c for multi-line replies. Although this vulnerability affects the client side of OpenSMTPD, it is possible to attack a server because the server code launches the client code during bounce handling.

OpenSMTPD before 6.6.4 allows local users to read arbitrary files (e.g., on some Linux distributions) because of a combination of an untrusted search path in makemap.c and race conditions in the offline functionality in smtpd.c.

kernel: use-after-free in n_tty_receive_buf_common function in drivers/tty/n_tty.c

There is a use-after-free vulnerability in the Linux kernel through 5.5.2 in the n_tty_receive_buf_common function in drivers/tty/n_tty.c.

cloud-init: Too short random password length in cc_set_password in config/cc_set_passwords.py

In cloud-init through 19.4, rand_user_password in cloudinit/config/cc_set_passwords.py has a small default pwlen value, which makes it easier for attackers to guess passwords.

cloud-init: Use of random.choice when generating random password

cloud-init through 19.4 relies on Mersenne Twister for a random password, which makes it easier for attackers to predict passwords, because rand_str in cloudinit/util.py calls the random.choice function.

update-policy rules of type "subdomain" are enforced incorrectly

In BIND 9.9.12 -> 9.9.13, 9.10.7 -> 9.10.8, 9.11.3 -> 9.11.21, 9.12.1 -> 9.16.5, 9.17.0 -> 9.17.3, also affects 9.9.12-S1 -> 9.9.13-S1, 9.11.3-S1 -> 9.11.21-S1 of the BIND 9 Supported Preview Edition, An attacker who has been granted privileges to change a specific subset of the zone's content could abuse these unintended additional privileges to update other contents of the zone.

A flaw in native PKCS#11 code can lead to a remotely triggerable assertion failure in pk11.c

In BIND 9.10.0 -> 9.11.21, 9.12.0 -> 9.16.5, 9.17.0 -> 9.17.3, also affects 9.10.5-S1 -> 9.11.21-S1 of the BIND 9 Supported Preview Edition, An attacker that can reach a vulnerable system with a specially crafted query packet can trigger a crash. To be vulnerable, the system must: * be running BIND that was built with "--enable-native-pkcs11" * be signing one or more zones with an RSA key * be able to receive queries from a possible attacker

A truncated TSIG response can lead to an assertion failure

In BIND 9.0.0 -> 9.11.21, 9.12.0 -> 9.16.5, 9.17.0 -> 9.17.3, also affects 9.9.3-S1 -> 9.11.21-S1 of the BIND 9 Supported Preview Edition, An attacker on the network path for a TSIG-signed request, or operating the server receiving the TSIG-signed request, could send a truncated response to that request, triggering an assertion failure, causing the server to exit. Alternately, an off-path attacker would have to correctly guess when a TSIG-signed request was sent, along with other characteristics of the packet and message, and spoof a truncated response to trigger an assertion failure, causing the server to exit.

Attempting QNAME minimization after forwarding can lead to an assertion failure in resolver.c

In BIND 9.14.0 -> 9.16.5, 9.17.0 -> 9.17.3, If a server is configured with both QNAME minimization and 'forward first' then an attacker who can send queries to it may be able to trigger the condition that will cause the server to crash. Servers that 'forward only' are not affected.

bind: A specially crafted large TCP payload can trigger an assertion failure in tcpdns.c

In BIND 9.15.6 -> 9.16.5, 9.17.0 -> 9.17.3, An attacker who can establish a TCP connection with the server and send data on that connection can exploit this to trigger the assertion failure, causing the server to exit.

A buffer boundary check assertion in rdataset.c can fail incorrectly during zone transfer

An attacker who is permitted to send zone data to a server via zone transfer can exploit this to intentionally trigger the assertion failure with a specially constructed zone, denying service to clients.

A logic error in code which checks TSIG validity can be used to trigger an assertion failure in tsig.c

Using a specially-crafted message, an attacker may potentially cause a BIND server to reach an inconsistent state if the attacker knows (or successfully guesses) the name of a TSIG key used by the server. Since BIND, by default, configures a local session key even on servers whose configuration does not otherwise make use of it, almost all current BIND servers are vulnerable. In releases of BIND dating from March 2018 and after, an assertion check in tsig.c detects this inconsistent state and deliberately exits. Prior to the introduction of the check the server would continue operating in an inconsistent state, with potentially harmful results.

squid: Buffer Overflow in ext_lm_group_acl helper

An issue was discovered in Squid before 4.10. Due to incorrect input validation, the NTLM authentication credentials parser in ext_lm_group_acl may write to memory outside the credentials buffer. On systems with memory access protections, this can result in the helper process being terminated unexpectedly. This leads to the Squid process also terminating and a denial of service for all clients using the proxy.

squid: Buffer overflow in reverse-proxy configurations

An issue was discovered in Squid before 4.10. Due to incorrect buffer management, a remote client can cause a buffer overflow in a Squid instance acting as a reverse proxy.

squid: Improper input validation issues in HTTP Request processing

An issue was discovered in Squid before 4.10. Due to incorrect input validation, it can interpret crafted HTTP requests in unexpected ways to access server resources prohibited by earlier security filters.

rubygem-rack: percent-encoded cookies can be used to overwrite existing prefixed cookie names

A reliance on cookies without validation/integrity check security vulnerability exists in rack < 2.2.3, rack < 2.1.4 that makes it is possible for an attacker to forge a secure or host-only cookie prefix.

rubygem-rack: directory traversal in Rack::Directory

A directory traversal vulnerability exists in rack < 2.2.0 that allows an attacker perform directory traversal vulnerability in the Rack::Directory app that is bundled with Rack which could result in information disclosure.