In the Linux kernel, the following vulnerability has been resolved:
A flaw was found in OpenSSH. A local unprivileged attacker on a Linux client host can hijack client-side X11 forwarding connections. This is possible by pre-binding the preferred abstract X socket name when X11 forwarding is enabled and a local UNIX-domain X socket is used. A successful attack can compromise the confidentiality of forwarded X11 traffic, including sensitive window contents and input, and may allow some manipulation of the forwarded session.
A flaw was found in OpenSSH. A malicious SSH server can exploit a double free vulnerability in the Diffie-Hellman Group Exchange (DH-GEX) client path. This occurs during FIPS (Federal Information Processing Standards) mode known-group validation when the client processes attacker-controlled DH-GEX group parameters. Successful exploitation leads to client-side process termination, resulting in a Denial of Service (DoS).
A flaw was found in the libblkid library of util-linux. During nested partition probing, the BSD, Minix, Solaris x86, and UnixWare partition probers cache a raw pointer to a parent partition entry in a dynamically allocated array. When subsequent partition additions cause the array to be reallocated, this pointer becomes stale, leading to a heap use-after-free read. An attacker who can present a crafted block device image (for example, via USB insertion or a loop-mounted disk image) can trigger this flaw without user interaction, as libblkid is invoked automatically by udev/udisks as root on block-device hot-plug events. This could lead to limited information disclosure or denial of service.
A flaw was found in the ZeroMQ server in versions before 4.3.3. This flaw allows a malicious client to cause a stack buffer overflow on the server by sending crafted topic subscription requests and then unsubscribing. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
An out of bounds read flaw was found in the Skia component of the Chromium browser.
Upstream bug(s):
https://code.google.com/p/chromium/issues/detail?id=883596
External References:
https://chromereleases.googleblog.com/2019/03/stable-channel-update-for-desktop12.html
A flaw was found in libsoup. When handling an incoming WebSocket Pong frame, SoupWebsocketConnection emitted the ::pong signal with a GByteArray pointer even though the signal is declared to pass a GBytes. Applications connecting a handler that follows the documented GBytes API can trigger heap corruption or a crash upon receiving a crafted Pong.
A flaw was found in libsoup. When reassembling fragmented WebSocket messages into a GByteArray, libsoup did not adequately cap total message size against the limits of the underlying buffer type. A remote peer could send fragments that caused size truncation while the implementation still used the full length, leading to heap corruption or a crash.
A flaw was found in libsoup. When constructing a masked WebSocket client frame for a very large outgoing payload, size values passed to GByteArray allocation APIs could be truncated while the masking routine still used the full length, causing a heap buffer overflow.
A flaw was found in libsoup. When max-incoming-payload-size is unlimited (0), SoupWebsocketConnection could grow its incoming GByteArray based on an attacker-controlled frame length until the length wrapped, causing a heap buffer overflow while reading frame data.
A flaw was found in libsoup. When the permessage-deflate WebSocket extension compresses a very large outgoing message, truncated size calculations used for GByteArray growth could wrap, causing zlib to write past the allocated buffer and resulting in a heap buffer overflow.
A flaw was found in GLib. The D-Bus client-side implementation of the DBUSCOOKIESHA1 SASL authentication mechanism does not validate the cookiecontext parameter received from the server. A malicious D-Bus server can supply a cookiecontext containing path traversal sequences, causing the client to read an arbitrary file and exfiltrate sensitive data by verifying guessed file contents against a generated hash.
A flaw was found in GLib. An out-of-bounds read of only 2 bytes can occur in the gdatetimegetymd function in the glib/gdatetime.c file when an invalid GDateTime object produced by the gdatetimeaddfull function is processed. This flaw can corrupt the date output and potentially cause logic errors that may lead to a denial of service.
A flaw was found in GLib. An off-by-one error can occur in the gvstupleisnormal function in the glib/gvariant-serialiser.c file when doing an alignment padding check because the bounds check uses instead of =, causing an out-of-bounds read of only 1 byte. This issue can cause a minor information disclosure of 1 byte and a denial of service when the out-of-bounds read crosses a page boundary.
A flaw was found in GLib. A buffer over-read can occur in the gregexreplace function when used with the GREGEXRAW compile flag and case-change replacement escapes because the stringappend function processes matched substrings using UTF-8 functions that assume valid UTF-8 input, even when the string is treated as raw bytes. This vulnerability can cause a minor information disclosure of 1-5 bytes and a denial of service when the buffer over-read crosses a page boundary.
A flaw was found in GLib. A buffer over-read can occur in giochannelreadlinebackend() in the giochannel.c file when a custom line terminator with a length greater than one is set, causing memcmp to read past the GString buffer. This vulnerability can cause a minor information disclosure of 7 bytes or a denial of service when the buffer over-read crosses a page boundary.
A flaw was found in GLib. An off-by-one error can occur in the gkeyfilegetlocalestringlist function in the gkeyfile.c file when loading a key file with an empty value. This flaw can cause an out-of-bounds access of 1 byte or a denial of service when the out-of-bounds access crosses a page boundary.
A flaw in the Linux Kernel found. If unprivileged users can mount FUSE filesystems, then can trigger use after free (UAF) that reads of write() buffers, allowing theft of (partial) /etc/shadow hashes or any other data from filesystem.
FUSE allows the userspace filesystem to specify on FUSEOPEN whether the file should use the normal kernel pagecache for handling read()/write() or just send FUSEREAD/FUSEWRITE requests directly to the userspace filesystem (using the flag FOPENDIRECTIO in fuseopenout::openflags).
In FOPENDIRECTIO mode, fusefilewriteiter() calls fusedirectwriteiter(), which normally calls fusedirectio(), which then imports the write buffer with fusegetuserpages(), which uses iovitergetpages() to grab references to userspace pages instead of actually copying memory.
On the filesystem device side, these pages can then either be read to userspace (via fusedevread()), or splice()d over into a pipe using fusedevspliceread() as pipe buffers with &nostealpipebufops.
This is wrong because after fusedevdoread() unlocks the FUSE request, the userspace filesystem can mark the request as completed, causing write() to return. At that point, the write buffer may be reused for other purposes, and the userspace filesystem should no longer have access to it.
An out-of-bounds (OOB) memory write flaw was found in listdevices in drivers/md/dm-ioctl.c in the Multi-device driver module in the Linux kernel before 5.12. A bound check failure allows an attacker with special user (CAPSYSADMIN) privilege to gain access to out-of-bounds memory leading to a system crash or a leak of internal kernel information. The highest threat from this vulnerability is to system availability.
A race problem was seen in the vtkioctl in drivers/tty/vt/vtioctl.c in the Linux kernel, which may cause an out of bounds read in vt as the write access to vcmode is not protected by lock-in vtioctl (KDSETMDE). The highest threat from this vulnerability is to data confidentiality.
A race condition accessing file object in the Linux kernel OverlayFS subsystem was found in the way users do rename in specific way with OverlayFS. A local user could use this flaw to crash the system.
A flaw was found in the Linux kernel’s implementation of MIDI, where an attacker with a local account and the permissions to issue ioctl commands to midi devices could trigger a use-after-free issue. A write to this specific memory while freed and before use causes the flow of execution to change and possibly allow for memory corruption or privilege escalation. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
A flaw in ICMP packets in the Linux kernel may allow an attacker to quickly scan open UDP ports. This flaw allows an off-path remote attacker to effectively bypass source port UDP randomization. Software that relies on UDP source port randomization are indirectly affected as well on the Linux Based Products (RUGGEDCOM RM1224: All versions between v5.0 and v6.4, SCALANCE M-800: All versions between v5.0 and v6.4, SCALANCE S615: All versions between v5.0 and v6.4, SCALANCE SC-600: All versions prior to v2.1.3, SCALANCE W1750D: v8.3.0.1, v8.6.0, and v8.7.0, SIMATIC Cloud Connect 7: All versions, SIMATIC MV500 Family: All versions, SIMATIC NET CP 1243-1 (incl. SIPLUS variants): Versions 3.1.39 and later, SIMATIC NET CP 1243-7 LTE EU: Version
A flaw was found in Linux Kernel, where a race in KDGKBSENT and KDSKBSENT leads to use-after-free read in vtdokdgkbioctl
References: https://groups.google.com/g/syzkaller-bugs/c/kZsmxkpq3UI/m/J35PFexWBgAJ?pli=1
A flaw was found in the Linux kernel netfilter implementation in versions prior to 5.5-rc7. A user with root (CAPSYSADMIN) access is able to panic the system when issuing netfilter netflow commands.
In tgmdmattinit of tt.c, there is a possible kernel memory corruption due to a use after free. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.
A flaw was found in the Linux Kernel. A use-after-free vulnerability was discovered in the ftrace ring buffer resizing logic due to a race condition.
Reference and upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=bbeb97464eefc65f506084fd9f18f21653e01137
A flaw was found in the Linux kernel’s KVM when attempting to set a SynIC IRQ. This issue makes it possible for a misbehaving VMM to write to SYNIC/STIMER MSRs, causing a NULL pointer dereference. This flaw allows an unprivileged local attacker on the host to issue specific ioctl calls, causing a kernel oops condition that results in a denial of service.
A vulnerability was found in OpenSSL 1.0.2. When an application encounters a fatal protocol error and then calls SSLshutdown() twice, OpenSSL can respond differently to the calling application if a 0 byte record is received with invalid padding compared to if a 0 byte record is received with an invalid MAC. This difference in behaviour can be detected by a remote peer, then this amounts to a padding oracle that could be used to decrypt data. In order for this to be exploitable "non-stitched" ciphersuites must be in use. Also the application must call SSLshutdown() twice even if a protocol error has occurred (applications should not do this but some do anyway). AEAD ciphersuites are not impacted. This issue does not impact OpenSSL 1.1.1 or 1.1.0.
Upstream bug: https://www.openssl.org/news/secadv/20190226.txt
Upstream Patch: https://github.com/openssl/openssl/commit/e9bbefbf0f24c57645e7ad6a5a71ae649d18ac8e
A configuration-dependent issue in rsyslog's optional imptcp input module can allow an unauthenticated remote peer to crash rsyslogd. The issue is not active in a default installation. Exploitation requires all of the following:
imptcp is explicitly loaded. An imptcp listener uses the non-default framing.delimiter.regex mode. An attacker can establish a TCP connection to that listener.
A crafted input sequence during oversize-frame recovery can cause an invalid internal message length and terminate rsyslogd. No confidentiality or integrity impact, privilege escalation, or code execution has been identified. imtcp and the default imptcp framing modes are not affected.