Security Vulnerabilities - CVEs Published In 2020
A lack of input validation and access controls in Lua CGIs on D-Link DSR VPN routers may result in arbitrary input being passed to system command APIs, resulting in arbitrary command execution with root privileges. This affects DSR-150, DSR-250, DSR-500, and DSR-1000AC with firmware 3.14 and 3.17.
CVSS Score
8.8
EPSS Score
0.005
Published
2020-12-15
An issue was discovered on D-Link DSR-250 3.17 devices. Insufficient validation of configuration file checksums could allow a remote, authenticated attacker to inject arbitrary crontab entries into saved configurations before uploading. These entries are executed as root.
CVSS Score
8.8
EPSS Score
0.003
Published
2020-12-15
An issue was discovered on D-Link DSR-250 3.17 devices. Certain functionality in the Unified Services Router web interface could allow an authenticated attacker to execute arbitrary commands, due to a lack of validation of inputs provided in multipart HTTP POST requests.
CVSS Score
8.8
EPSS Score
0.015
Published
2020-12-15
A flaw was found in Keycloak before 13.0.0 where an external identity provider, after successful authentication, redirects to a Keycloak endpoint that accepts multiple invocations with the use of the same "state" parameter. This flaw allows a malicious user to perform replay attacks.
CVSS Score
4.9
EPSS Score
0.002
Published
2020-12-15
The length of the input fields of Host Engineering H0-ECOM100, H2-ECOM100, and H4-ECOM100 modules are verified only on the client side when receiving input from the configuration web server, which may allow an attacker to bypass the check and send input to crash the device.
CVSS Score
7.5
EPSS Score
0.002
Published
2020-12-15
A flaw was found in Keycloak before 13.0.0, where it is possible to force the server to call out an unverified URL using the OIDC parameter request_uri. This flaw allows an attacker to use this parameter to execute a Server-side request forgery (SSRF) attack.
CVSS Score
5.3
EPSS Score
0.918
Published
2020-12-15
An issue was discovered in Xen through 4.14.x. Neither xenstore implementation does any permission checks when reporting a xenstore watch event. A guest administrator can watch the root xenstored node, which will cause notifications for every created, modified, and deleted key. A guest administrator can also use the special watches, which will cause a notification every time a domain is created and destroyed. Data may include: number, type, and domids of other VMs; existence and domids of driver domains; numbers of virtual interfaces, block devices, vcpus; existence of virtual framebuffers and their backend style (e.g., existence of VNC service); Xen VM UUIDs for other domains; timing information about domain creation and device setup; and some hints at the backend provisioning of VMs and their devices. The watch events do not contain values stored in xenstore, only key names. A guest administrator can observe non-sensitive domain and device lifecycle events relating to other guests. This information allows some insight into overall system configuration (including the number and general nature of other guests), and configuration of other guests (including the number and general nature of other guests' devices). This information might be commercially interesting or might make other attacks easier. There is not believed to be exposure of sensitive data. Specifically, there is no exposure of VNC passwords, port numbers, pathnames in host and guest filesystems, cryptographic keys, or within-guest data.
CVSS Score
2.3
EPSS Score
0.001
Published
2020-12-15
An issue was discovered in Xen through 4.14.x. Access rights of Xenstore nodes are per domid. Unfortunately, existing granted access rights are not removed when a domain is being destroyed. This means that a new domain created with the same domid will inherit the access rights to Xenstore nodes from the previous domain(s) with the same domid. Because all Xenstore entries of a guest below /local/domain/<domid> are being deleted by Xen tools when a guest is destroyed, only Xenstore entries of other guests still running are affected. For example, a newly created guest domain might be able to read sensitive information that had belonged to a previously existing guest domain. Both Xenstore implementations (C and Ocaml) are vulnerable.
CVSS Score
8.8
EPSS Score
0.001
Published
2020-12-15
An issue was discovered in Xen through 4.14.x. A guest may access xenstore paths via absolute paths containing a full pathname, or via a relative path, which implicitly includes /local/domain/$DOMID for their own domain id. Management tools must access paths in guests' namespaces, necessarily using absolute paths. oxenstored imposes a pathname limit that is applied solely to the relative or absolute path specified by the client. Therefore, a guest can create paths in its own namespace which are too long for management tools to access. Depending on the toolstack in use, a malicious guest administrator might cause some management tools and debugging operations to fail. For example, a guest administrator can cause "xenstore-ls -r" to fail. However, a guest administrator cannot prevent the host administrator from tearing down the domain. All systems using oxenstored are vulnerable. Building and using oxenstored is the default in the upstream Xen distribution, if the Ocaml compiler is available. Systems using C xenstored are not vulnerable.
CVSS Score
6.0
EPSS Score
0.001
Published
2020-12-15
An issue was discovered in Xen through 4.14.x. Xenstored and guests communicate via a shared memory page using a specific protocol. When a guest violates this protocol, xenstored will drop the connection to that guest. Unfortunately, this is done by just removing the guest from xenstored's internal management, resulting in the same actions as if the guest had been destroyed, including sending an @releaseDomain event. @releaseDomain events do not say that the guest has been removed. All watchers of this event must look at the states of all guests to find the guest that has been removed. When an @releaseDomain is generated due to a domain xenstored protocol violation, because the guest is still running, the watchers will not react. Later, when the guest is actually destroyed, xenstored will no longer have it stored in its internal data base, so no further @releaseDomain event will be sent. This can lead to a zombie domain; memory mappings of that guest's memory will not be removed, due to the missing event. This zombie domain will be cleaned up only after another domain is destroyed, as that will trigger another @releaseDomain event. If the device model of the guest that violated the Xenstore protocol is running in a stub-domain, a use-after-free case could happen in xenstored, after having removed the guest from its internal data base, possibly resulting in a crash of xenstored. A malicious guest can block resources of the host for a period after its own death. Guests with a stub domain device model can eventually crash xenstored, resulting in a more serious denial of service (the prevention of any further domain management operations). Only the C variant of Xenstore is affected; the Ocaml variant is not affected. Only HVM guests with a stubdom device model can cause a serious DoS.
CVSS Score
6.5
EPSS Score
0.001
Published
2020-12-15