CVE-2021-28503
CRITICALCVSS 9.8/10EPSS 0.72%
Last modified
CVE-2021-28503 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. The impact of this vulnerability is that Arista's EOS eAPI may skip re-evaluating user credentials when certificate based authentication is used, which allows remote attackers to access the device via eAPI.. EPSS estimates a 0.72% chance of exploitation in the next 30 days.
Description
The impact of this vulnerability is that Arista's EOS eAPI may skip re-evaluating user credentials when certificate based authentication is used, which allows remote attackers to access the device via eAPI.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Arista | Eos | >= 4.22, <= 4.22.9m |
| Arista | Eos | >= 4.23, <= 4.23.9 |
| Arista | Eos | >= 4.24, <= 4.24.7 |
| Arista | Eos | >= 4.25, <= 4.25.5 |
| Arista | Eos | >= 4.26, <= 4.26.2 |
References
- https://www.arista.com/en/support/advisories-notices/security-advisories/13605-security-advisory-0072Mitigation, Patch, Vendor Advisory
- https://www.arista.com/en/support/advisories-notices/security-advisories/13605-security-advisory-0072Mitigation, Patch, Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Modified
Frequently Asked Questions
What is CVE-2021-28503?
The impact of this vulnerability is that Arista's EOS eAPI may skip re-evaluating user credentials when certificate based authentication is used, which allows remote attackers to access the device via eAPI.
How severe is CVE-2021-28503?
CVE-2021-28503 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.72% probability of exploitation in the next 30 days.
How do I fix CVE-2021-28503?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2021
- CVE-2021-28496On systems running Arista EOS and CloudEOS with the affected…6.5
- CVE-2021-28497In Arista's MOS (Metamako Operating System) software which i…7.8
- CVE-2021-28498In Arista's MOS (Metamako Operating System) software which i…7.8
- CVE-2021-28499In Arista's MOS (Metamako Operating System) software which i…5.5
- CVE-2021-28500An issue has recently been discovered in Arista EOS where th…7.8
- CVE-2021-28501An issue has recently been discovered in Arista EOS where th…7.8
- CVE-2021-28504On Arista Strata family products which have “TCAM profile” f…7.5
- CVE-2021-28505On affected Arista EOS platforms, if a VXLAN match rule exis…7.5
- CVE-2021-28506An issue has recently been discovered in Arista EOS where ce…9.1
- CVE-2021-28507An issue has recently been discovered in Arista EOS where, u…7.1
- CVE-2021-28508This advisory documents the impact of an internally found vu…6.1
- CVE-2021-28509This advisory documents the impact of an internally found vu…6.1
Are you affected by CVE-2021-28503?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST