long running loops in grant table handling In order to properly monitor resource use, Xen maintains information on the grant mappings a domain may create to map grants offered by other domains. In the process of carrying out certain actions, Xen would iterate over all such entries, including ones which aren't in use anymore and some which may have been created but never used. If the number of entries for a given domain is large enough, this iterating of the entire table may tie up a CPU for too long, starving other domains or causing issues in the hypervisor itself. Note that a domain may map its own grants, i.e. there is no need for multiple domains to be involved here. A pair of "cooperating" guests may, however, cause the effects to be more severe.

grant table v2 status pages may remain accessible after de-allocation Guest get permitted access to certain Xen-owned pages of memory. The majority of such pages remain allocated / associated with a guest for its entire lifetime. Grant table v2 status pages, however, get de-allocated when a guest switched (back) from v2 to v1. The freeing of such pages requires that the hypervisor know where in the guest these pages were mapped. The hypervisor tracks only one use within guest space, but racing requests from the guest to insert mappings of these pages may result in any of them to become mapped in multiple locations. Upon switching back from v2 to v1, the guest would then retain access to a page that was freed and perhaps re-used for other purposes.

IOMMU page mapping issues on x86 T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Both AMD and Intel allow ACPI tables to specify regions of memory which should be left untranslated, which typically means these addresses should pass the translation phase unaltered. While these are typically device specific ACPI properties, they can also be specified to apply to a range of devices, or even all devices. On all systems with such regions Xen failed to prevent guests from undoing/replacing such mappings (CVE-2021-28694). On AMD systems, where a discontinuous range is specified by firmware, the supposedly-excluded middle range will also be identity-mapped (CVE-2021-28695). Further, on AMD systems, upon de-assigment of a physical device from a guest, the identity mappings would be left in place, allowing a guest continued access to ranges of memory which it shouldn't have access to anymore (CVE-2021-28696).

IOMMU page mapping issues on x86 T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Both AMD and Intel allow ACPI tables to specify regions of memory which should be left untranslated, which typically means these addresses should pass the translation phase unaltered. While these are typically device specific ACPI properties, they can also be specified to apply to a range of devices, or even all devices. On all systems with such regions Xen failed to prevent guests from undoing/replacing such mappings (CVE-2021-28694). On AMD systems, where a discontinuous range is specified by firmware, the supposedly-excluded middle range will also be identity-mapped (CVE-2021-28695). Further, on AMD systems, upon de-assigment of a physical device from a guest, the identity mappings would be left in place, allowing a guest continued access to ranges of memory which it shouldn't have access to anymore (CVE-2021-28696).

IOMMU page mapping issues on x86 T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Both AMD and Intel allow ACPI tables to specify regions of memory which should be left untranslated, which typically means these addresses should pass the translation phase unaltered. While these are typically device specific ACPI properties, they can also be specified to apply to a range of devices, or even all devices. On all systems with such regions Xen failed to prevent guests from undoing/replacing such mappings (CVE-2021-28694). On AMD systems, where a discontinuous range is specified by firmware, the supposedly-excluded middle range will also be identity-mapped (CVE-2021-28695). Further, on AMD systems, upon de-assigment of a physical device from a guest, the identity mappings would be left in place, allowing a guest continued access to ranges of memory which it shouldn't have access to anymore (CVE-2021-28696).

python-pillow: Excessive looping in BLP image reader

An issue was discovered in Pillow before 8.2.0. For BLP data, BlpImagePlugin did not properly check that reads (after jumping to file offsets) returned data. This could lead to a DoS where the decoder could be run a large number of times on empty data.

python-pillow: Excessive CPU use in EPS image reader

An issue was discovered in Pillow before 8.2.0. For EPS data, the readline implementation used in EPSImageFile has to deal with any combination of \r and \n as line endings. It used an accidentally quadratic method of accumulating lines while looking for a line ending. A malicious EPS file could use this to perform a DoS of Pillow in the open phase, before an image was accepted for opening.

python-pillow: Infinite loop in FLI image reader

An issue was discovered in Pillow before 8.2.0. For FLI data, FliDecode did not properly check that the block advance was non-zero, potentially leading to an infinite loop on load.

python-pillow: Excessive memory allocation in PSD image reader

An issue was discovered in Pillow before 8.2.0. PSDImagePlugin.PsdImageFile lacked a sanity check on the number of input layers relative to the size of the data block. This could lead to a DoS on Image.open prior to Image.load.

squid: denial of service in HTTP response processing

An issue was discovered in Squid 4.x before 4.15 and 5.x before 5.0.6. If a remote server sends a certain response header over HTTP or HTTPS, there is a denial of service. This header can plausibly occur in benign network traffic.

kernel: buffer overflow in rtw_wx_set_scan function in drivers/staging/rtl8188eu/os_dep/ioctl_linux.c

rtw_wx_set_scan in drivers/staging/rtl8188eu/os_dep/ioctl_linux.c in the Linux kernel through 5.11.6 allows writing beyond the end of the ->ssid[] array. NOTE: from the perspective of kernel.org releases, CVE IDs are not normally used for drivers/staging/* (unfinished work); however, system integrators may have situations in which a drivers/staging issue is relevant to their own customer base.

django: potential directory-traversal via uploaded files

In Django 2.2 before 2.2.20, 3.0 before 3.0.14, and 3.1 before 3.1.8, MultiPartParser allowed directory traversal via uploaded files with suitably crafted file names. Built-in upload handlers were not affected by this vulnerability.

squid: denial of service issue in Cache Manager

An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to incorrect parser validation, it allows a Denial of Service attack against the Cache Manager API. This allows a trusted client to trigger memory leaks that. over time, lead to a Denial of Service via an unspecified short query string. This attack is limited to clients with Cache Manager API access privilege.

squid: denial of service in URN processing

An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to a buffer-management bug, it allows a denial of service. When resolving a request with the urn: scheme, the parser leaks a small amount of memory. However, there is an unspecified attack methodology that can easily trigger a large amount of memory consumption.

gnome-autoar: Directory traversal via directory symbolic links pointing outside of the destination directory (incomplete CVE-2020-36241 fix)

autoar-extractor.c in GNOME gnome-autoar before 0.3.1, as used by GNOME Shell, Nautilus, and other software, allows Directory Traversal during extraction because it lacks a check of whether a file's parent is a symlink in certain complex situations. NOTE: this issue exists because of an incomplete fix for CVE-2020-36241.

Apache Subversion SVN authz protected copyfrom paths regression

Apache Subversion SVN authz protected copyfrom paths regression Subversion servers reveal 'copyfrom' paths that should be hidden according to configured path-based authorization (authz) rules. When a node has been copied from a protected location, users with access to the copy can see the 'copyfrom' path of the original. This also reveals the fact that the node was copied. Only the 'copyfrom' path is revealed; not its contents. Both httpd and svnserve servers are vulnerable.

varnish-modules: NULL pointer dereference in Varnish Cache via header.append() and header.copy() functions

Varnish varnish-modules before 0.17.1 allows remote attackers to cause a denial of service (daemon restart) in some configurations. This does not affect organizations that only install the Varnish Cache product; however, it is common to install both Varnish Cache and varnish-modules. Specifically, an assertion failure or NULL pointer dereference can be triggered in Varnish Cache through the varnish-modules header.append() and header.copy() functions. For some Varnish Configuration Language (VCL) files, this gives remote clients an opportunity to cause a Varnish Cache restart. A restart reduces overall availability and performance due to an increased number of cache misses, and may cause higher load on backend servers.

An issue was discovered in the /api/connector endpoint handler in Yubico yubihsm-connector before 3.0.1 (in YubiHSM SDK before 2021.04). The handler did not validate the length of the request, which can lead to a state where yubihsm-connector becomes stuck in a loop waiting for the YubiHSM to send it data, preventing any further operations until the yubihsm-connector is restarted. An attacker can send 0, 1, or 2 bytes to trigger this.

kernel: fastrpc_internal_invoke in drivers/misc/fastrpc.c does not prevent user applications from sending kernel RPC messages

An issue was discovered in the Linux kernel through 5.11.6. fastrpc_internal_invoke in drivers/misc/fastrpc.c does not prevent user applications from sending kernel RPC messages, aka CID-20c40794eb85. This is a related issue to CVE-2019-2308.

jetty: Symlink directory exposes webapp directory contents

In Eclipse Jetty 9.4.32 to 9.4.38, 10.0.0.beta2 to 10.0.1, and 11.0.0.beta2 to 11.0.1, if a user uses a webapps directory that is a symlink, the contents of the webapps directory is deployed as a static webapp, inadvertently serving the webapps themselves and anything else that might be in that directory.