CVE-2021-22893: Ivanti Pulse Connect Secure Use-After-Free Vulnerability

Vulnerability summary

CVE-2021-22893 is a critical (CVSS 10.0) Improper Authentication vulnerability in Ivanti Pulse Connect Secure. It is known to be exploited: CISA lists it, first on 03-11-2021. It has been used in ransomware campaigns. EPSS estimates a 47.17% chance of exploitation in the next 30 days, higher than 98.8% of scored vulnerabilities.

Timeline

1. 23-04-2021
   PublishedVulnerability first disclosed.
2. 03-11-2021
   Added to CISA KEVIvanti Pulse Connect Secure Use-After-Free Vulnerability
3. 03-05-2022
   CISA remediation dueApply updates per vendor instructions.
4. 12-08-2026
   Last modifiedVulnerability information updated.

Description

Pulse Connect Secure 9.0R3/9.1R1 and higher is vulnerable to an authentication bypass vulnerability exposed by the Windows File Share Browser and Pulse Secure Collaboration features of Pulse Connect Secure that can allow an unauthenticated user to perform remote arbitrary code execution on the Pulse Connect Secure gateway. This vulnerability has been exploited in the wild.

• CWE-287Improper AuthenticationWhen an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
• CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.