CVE-2021-26377
Citrix XenServer Integer Overflow Denial of Service
Description
Insufficient parameter validation while allocating process space in the Trusted OS (TOS) may allow for a malicious userspace process to trigger an integer overflow, leading to a potential denial of service.
INFO
Published Date :
Sept. 6, 2025, 4:15 p.m.
Last Modified :
June 17, 2026, 3:43 a.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2021-26377
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | b58fc414-a1e4-4f92-9d70-1add41838648 | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Implement robust validation for process space allocation parameters.
- Address integer overflow vulnerabilities in the Trusted OS.
- Apply security patches to the Trusted OS.
- Monitor system resources for signs of DoS.
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-2021-26377.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-26377 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-2021-26377
weaknesses.
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).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-26377 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-26377 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]
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'AMD', 'product': 'AMD Ryzen™ 5000 Series Processors with Radeon™ Graphics', 'versions': [{'status': 'unaffected', 'version': 'CezannePI-FP6 1.0.0.8'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Ryzen™ Threadripper™ 3000 Series Processors', 'versions': [{'status': 'unaffected', 'version': 'CastlePeakPI-SP3r3 1.0.0.7'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Ryzen™ Threadripper™ PRO 3000WX Series Processors', 'versions': [{'status': 'unaffected', 'version': 'CastlePeakWSPI-sWRX8 1.0.0.9'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Ryzen™ 5000 Series Mobile Processors with Radeon™ Graphics', 'versions': [{'status': 'unaffected', 'version': 'CezannePI-FP6 1.0.0.8'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Ryzen™ Threadripper™ PRO 5000 WX-Series Processors', 'versions': [{'status': 'unaffected', 'version': 'ChagallWSPI-sWRX8 1.0.0.2'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Ryzen™ 5000 Series Desktop Processors', 'versions': [{'status': 'unaffected', 'version': 'ComboAM4v2 PI 1.2.0.5'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Athlon™ 3000 Series Mobile Processors with Radeon™ Graphics', 'versions': [{'status': 'unaffected', 'version': 'PicassoPI-FP5 1.0.0.E'}, {'status': 'unaffected', 'version': 'PollockPI-FT5 1.0.0.4'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Ryzen™ 5000 Series Mobile Processors with Radeon™ Graphics', 'versions': [{'status': 'unaffected', 'version': 'CezannePI-FP6 1.0.0.8'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Ryzen™ 3000 Series Desktop Processors', 'versions': [{'status': 'unaffected', 'version': 'ComboAM4PI 1.0.0.9/ ComboAM4 V2 PI 1.2.0.8'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Ryzen™ 7030 Series Mobile processors with Radeon™ Graphics', 'versions': [{'status': 'unaffected', 'version': 'CezannePI-FP6 1.0.0.8'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Ryzen™ 4000 Series Desktop Processors', 'versions': [{'status': 'unaffected', 'version': 'ComboAM4v2 PI 1.2.0.5'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Ryzen™ 4000 Series Mobile Processors with Radeon™ Graphics', 'versions': [{'status': 'unaffected', 'version': 'RenoirPI-FP6 1.0.0.8'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Ryzen™ 5000 Series Desktop Processors', 'versions': [{'status': 'unaffected', 'version': 'ComboAM4 V2 PI 1.2.0.8'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Ryzen™ 6000 Series Processors with Radeon™ Graphics', 'versions': [{'status': 'unaffected', 'version': 'RembrandtPI-FP7_0.0.8.0 RC1'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Ryzen™ Embedded R1000 Series Processors', 'versions': [{'status': 'unaffected', 'version': 'EmbeddedPI-FP5_1.2.0.A'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Ryzen™ Embedded R2000 Series Processors', 'versions': [{'status': 'unaffected', 'version': 'EmbeddedR2KPI-FP5_1.0.0.2'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Ryzen™ Embedded 5000 Series Processors', 'versions': [{'status': 'unaffected', 'version': 'EmbAM4PI 1.0.0.2'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Ryzen™ Embedded V1000 Series Processors', 'versions': [{'status': 'unaffected', 'version': 'EmbeddedPI-FP5_1.2.0.A'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Ryzen™ Embedded V2000 Series Processors', 'versions': [{'status': 'unaffected', 'version': 'EmbeddedPI-FP6_1.0.0.6'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Ryzen™ Embedded V3000 Series Processors', 'versions': [{'status': 'unaffected', 'version': 'EmbeddedPI-FP7r2_1000'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Radeon™ RX 5000 Series Graphics Products', 'versions': [{'status': 'unaffected', 'version': 'AMD Software: Adrenalin Edition 24.7.1 (24.10.29.01)'}, {'status': 'unaffected', 'version': 'AMD Software: PRO Edition 24.Q2 (24.10.20)'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Radeon™ PRO W5000 Series Graphics Products', 'versions': [{'status': 'unaffected', 'version': 'AMD Software: PRO Edition 24.Q2 (24.10.20)'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Radeon™ RX 6000 Series Graphics Products', 'versions': [{'status': 'unaffected', 'version': 'AMD Software: Adrenalin Edition 24.7.1 (24.10.29.01)'}, {'status': 'unaffected', 'version': 'AMD Software: PRO Edition 24.Q2 (24.10.20)'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Radeon™ PRO W6000 Series Graphics Products', 'versions': [{'status': 'unaffected', 'version': 'AMD Software: PRO Edition 24.Q2 (24.10.20)'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Radeon™ Instinct™ MI25 Graphics Products', 'versions': [{'status': 'unaffected', 'version': 'Contact your AMD Customer Engineering representative'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Radeon™ PRO V520 Graphics Products', 'versions': [{'status': 'unaffected', 'version': 'Contact your AMD Customer Engineering representative'}], 'defaultStatus': 'affected'}, {'vendor': 'AMD', 'product': 'AMD Radeon™ PRO V620 Graphics Products', 'versions': [{'status': 'unaffected', 'version': 'Contact your AMD Customer Engineering representative'}], 'defaultStatus': 'affected'}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2021-26377', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2025-09-08T13:46:56.766235Z'} -
New CVE Received by [email protected]
Sep. 06, 2025
Action Type Old Value New Value Added Description Insufficient parameter validation while allocating process space in the Trusted OS (TOS) may allow for a malicious userspace process to trigger an integer overflow, leading to a potential denial of service. Added CVSS V3.1 AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-190 Added Reference https://www.amd.com/en/resources/product-security/bulletin/AMD-SB-4012.html Added Reference https://www.amd.com/en/resources/product-security/bulletin/AMD-SB-5007.html Added Reference https://www.amd.com/en/resources/product-security/bulletin/AMD-SB-6018.html