Ubuntu Linux

LibreOffice has a feature where documents can specify that pre-installed macros can be executed on various script events such as mouse-over, document-open etc. Access is intended to be restricted to scripts under the share/Scripts/python, user/Scripts/python sub-directories of the LibreOffice install. Protection was added, to address CVE-2018-16858, to avoid a directory traversal attack where scripts in arbitrary locations on the file system could be executed. However this new protection could be bypassed by a URL encoding attack. In the fixed versions, the parsed url describing the script location is correctly encoded before further processing. This issue affects: Document Foundation LibreOffice versions prior to 6.2.6.Show less

LibreOffice is typically bundled with LibreLogo, a programmable turtle vector graphics script, which can execute arbitrary python commands contained with the document it is launched from. Protection was added, to address CVE-2019-9848, to block calling LibreLogo from document event script handers, e.g. mouse over. However LibreOffice also has a separate feature where documents can specify that pre-installed scripts can be executed on various global script events such as document-open, etc. In the fixed versions, global script event handlers are validated equivalently to document script event handlers. This issue affects: Document Foundation LibreOffice versions prior to 6.2.6.Show less

LibreOffice is typically bundled with LibreLogo, a programmable turtle vector graphics script, which can execute arbitrary python commands contained with the document it is launched from. LibreOffice also has a feature where documents can specify that pre-installed scripts can be executed on various document script events such as mouse-over, etc. Protection was added, to address CVE-2019-9848, to block calling LibreLogo from script event handers. However an insufficient url validation vulnerability in LibreOffice allowed malicious to bypass that protection and again trigger calling LibreLogo from script event handlers. This issue affects: Document Foundation LibreOffice versions prior to 6.2.6.Show less

The implementations of SAE and EAP-pwd in hostapd and wpa_supplicant 2.x through 2.8 are vulnerable to side-channel attacks as a result of observable timing differences and cache access patterns when Brainpool curves are used. An attacker may be able to gain leaked information from a side-channel attack that can be used for full password recovery.Show less

Due to incorrect string termination, Squid cachemgr.cgi 4.0 through 4.7 may access unallocated memory. On systems with memory access protections, this can cause the CGI process to terminate unexpectedly, resulting in a denial of service for all clients using it.Show less

The Bluetooth BR/EDR specification up to and including version 5.1 permits sufficiently low encryption key length and does not prevent an attacker from influencing the key length negotiation. This allows practical brute-force attacks (aka "KNOB") that can decrypt traffic and inject arbitrary ciphertext without the victim noticing.Show less

Some HTTP/2 implementations are vulnerable to a flood of empty frames, potentially leading to a denial of service. The attacker sends a stream of frames with an empty payload and without the end-of-stream flag. These frames can be DATA, HEADERS, CONTINUATION and/or PUSH_PROMISE. The peer spends time processing each frame disproportionate to attack bandwidth. This can consume excess CPU.Show less

Some HTTP/2 implementations are vulnerable to unconstrained interal data buffering, potentially leading to a denial of service. The attacker opens the HTTP/2 window so the peer can send without constraint; however, they leave the TCP window closed so the peer cannot actually write (many of) the bytes on the wire. The attacker then sends a stream of requests for a large response object. Depending on how the servers queue the responses, this can consume excess memory, CPU, or both.Show less

Some HTTP/2 implementations are vulnerable to a header leak, potentially leading to a denial of service. The attacker sends a stream of headers with a 0-length header name and 0-length header value, optionally Huffman encoded into 1-byte or greater headers. Some implementations allocate memory for these headers and keep the allocation alive until the session dies. This can consume excess memory.Show less

Some HTTP/2 implementations are vulnerable to a settings flood, potentially leading to a denial of service. The attacker sends a stream of SETTINGS frames to the peer. Since the RFC requires that the peer reply with one acknowledgement per SETTINGS frame, an empty SETTINGS frame is almost equivalent in behavior to a ping. Depending on how efficiently this data is queued, this can consume excess CPU, memory, or both.Show less

Some HTTP/2 implementations are vulnerable to a reset flood, potentially leading to a denial of service. The attacker opens a number of streams and sends an invalid request over each stream that should solicit a stream of RST_STREAM frames from the peer. Depending on how the peer queues the RST_STREAM frames, this can consume excess memory, CPU, or both.Show less

Some HTTP/2 implementations are vulnerable to resource loops, potentially leading to a denial of service. The attacker creates multiple request streams and continually shuffles the priority of the streams in a way that causes substantial churn to the priority tree. This can consume excess CPU.Show less

Some HTTP/2 implementations are vulnerable to window size manipulation and stream prioritization manipulation, potentially leading to a denial of service. The attacker requests a large amount of data from a specified resource over multiple streams. They manipulate window size and stream priority to force the server to queue the data in 1-byte chunks. Depending on how efficiently this data is queued, this can consume excess CPU, memory, or both.Show less

An issue was discovered in net/ipv6/ip6mr.c in the Linux kernel before 4.11. By setting a specific socket option, an attacker can control a pointer in kernel land and cause an inet_csk_listen_stop general protection fault, or potentially execute arbitrary code under certain circumstances. The issue can be triggered as root (e.g., inside a default LXC container or with the CAP_NET_ADMIN capability) or after namespace unsharing. This occurs because sk_type and protocol are not checked in the appropriate part of the ip6_mroute_* functions. NOTE: this affects Linux distributions that use 4.9.x longterm kernels before 4.9.187.Show less

When PHP EXIF extension is parsing EXIF information from an image, e.g. via exif_read_data() function, in PHP versions 7.1.x below 7.1.31, 7.2.x below 7.2.21 and 7.3.x below 7.3.8 it is possible to supply it with data what will cause it to read past the allocated buffer. This may lead to information disclosure or crash.Show less