CVE-2021-28687
Libxl Uninitialized Structure Crash Vulnerability in Xen Toolstack
Description
HVM soft-reset crashes toolstack libxl requires all data structures passed across its public interface to be initialized before use and disposed of afterwards by calling a specific set of functions. Many internal data structures also require this initialize / dispose discipline, but not all of them. When the "soft reset" feature was implemented, the libxl__domain_suspend_state structure didn't require any initialization or disposal. At some point later, an initialization function was introduced for the structure; but the "soft reset" path wasn't refactored to call the initialization function. When a guest nwo initiates a "soft reboot", uninitialized data structure leads to an assert() when later code finds the structure in an unexpected state. The effect of this is to crash the process monitoring the guest. How this affects the system depends on the structure of the toolstack. For xl, this will have no security-relevant effect: every VM has its own independent monitoring process, which contains no state. The domain in question will hang in a crashed state, but can be destroyed by `xl destroy` just like any other non-cooperating domain. For daemon-based toolstacks linked against libxl, such as libvirt, this will crash the toolstack, losing the state of any in-progress operations (localized DoS), and preventing further administrator operations unless the daemon is configured to restart automatically (system-wide DoS). If crashes "leak" resources, then repeated crashes could use up resources, also causing a system-wide DoS.
INFO
Published Date :
June 11, 2021, 3:15 p.m.
Last Modified :
Sept. 20, 2021, 1:51 p.m.
Source :
[email protected]
Remotely Exploitable :
No
Impact Score :
3.6
Exploitability Score :
1.8
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-28687
.
URL | Resource |
---|---|
https://security.gentoo.org/glsa/202107-30 | Third Party Advisory |
https://xenbits.xenproject.org/xsa/advisory-368.txt | Vendor Advisory |
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2021-28687
vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-28687
vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
Modified Analysis by [email protected]
Sep. 20, 2021
Action Type Old Value New Value Changed Reference Type https://security.gentoo.org/glsa/202107-30 No Types Assigned https://security.gentoo.org/glsa/202107-30 Third Party Advisory Changed CPE Configuration OR *cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:* versions from (including) 4.12 up to (including) 4.14 OR *cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:* versions from (including) 4.12 up to (including) 4.15.0 *cpe:2.3:o:xen:xen:4.15.0:rc1:*:*:*:*:*:* -
CVE Modified by [email protected]
Jul. 12, 2021
Action Type Old Value New Value Added Reference https://security.gentoo.org/glsa/202107-30 [No Types Assigned] -
Initial Analysis by [email protected]
Jun. 24, 2021
Action Type Old Value New Value Added CVSS V2 NIST (AV:L/AC:L/Au:N/C:N/I:N/A:C) Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Changed Reference Type https://xenbits.xenproject.org/xsa/advisory-368.txt No Types Assigned https://xenbits.xenproject.org/xsa/advisory-368.txt Vendor Advisory Added CWE NIST CWE-909 Added CPE Configuration OR *cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:* versions from (including) 4.12 up to (including) 4.14
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-28687
is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-28687
weaknesses.
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
0.04 }} 0.00%
score
0.10264
percentile