CVE Vulnerabilities

CVE-2021-22893

Use After Free

Published: Apr 23, 2021 | Modified: Feb 27, 2024
CVSS 3.x
10
CRITICAL
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CVSS 2.x
7.5 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P
RedHat/V2
RedHat/V3
Ubuntu

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.

Weakness

Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code.

Affected Software

Name Vendor Start Version End Version
Connect_secure Ivanti 9.0 (including) 9.0 (including)
Connect_secure Ivanti 9.0-r1 (including) 9.0-r1 (including)
Connect_secure Ivanti 9.0-r2 (including) 9.0-r2 (including)
Connect_secure Ivanti 9.0-r2.1 (including) 9.0-r2.1 (including)
Connect_secure Ivanti 9.0-r3 (including) 9.0-r3 (including)
Connect_secure Ivanti 9.0-r3.1 (including) 9.0-r3.1 (including)
Connect_secure Ivanti 9.0-r3.2 (including) 9.0-r3.2 (including)
Connect_secure Ivanti 9.0-r3.3 (including) 9.0-r3.3 (including)
Connect_secure Ivanti 9.0-r3.5 (including) 9.0-r3.5 (including)
Connect_secure Ivanti 9.0-r4 (including) 9.0-r4 (including)
Connect_secure Ivanti 9.0-r4.1 (including) 9.0-r4.1 (including)
Connect_secure Ivanti 9.0-r5.0 (including) 9.0-r5.0 (including)
Connect_secure Ivanti 9.0-r6.0 (including) 9.0-r6.0 (including)
Connect_secure Ivanti 9.1 (including) 9.1 (including)
Connect_secure Ivanti 9.1-r1 (including) 9.1-r1 (including)
Connect_secure Ivanti 9.1-r10.0 (including) 9.1-r10.0 (including)
Connect_secure Ivanti 9.1-r10.2 (including) 9.1-r10.2 (including)
Connect_secure Ivanti 9.1-r11.0 (including) 9.1-r11.0 (including)
Connect_secure Ivanti 9.1-r11.1 (including) 9.1-r11.1 (including)
Connect_secure Ivanti 9.1-r11.3 (including) 9.1-r11.3 (including)
Connect_secure Ivanti 9.1-r2 (including) 9.1-r2 (including)
Connect_secure Ivanti 9.1-r3 (including) 9.1-r3 (including)
Connect_secure Ivanti 9.1-r4 (including) 9.1-r4 (including)
Connect_secure Ivanti 9.1-r4.1 (including) 9.1-r4.1 (including)
Connect_secure Ivanti 9.1-r4.2 (including) 9.1-r4.2 (including)
Connect_secure Ivanti 9.1-r4.3 (including) 9.1-r4.3 (including)
Connect_secure Ivanti 9.1-r5 (including) 9.1-r5 (including)
Connect_secure Ivanti 9.1-r6 (including) 9.1-r6 (including)
Connect_secure Ivanti 9.1-r7 (including) 9.1-r7 (including)
Connect_secure Ivanti 9.1-r8 (including) 9.1-r8 (including)
Connect_secure Ivanti 9.1-r8.1 (including) 9.1-r8.1 (including)
Connect_secure Ivanti 9.1-r8.2 (including) 9.1-r8.2 (including)
Connect_secure Ivanti 9.1-r8.4 (including) 9.1-r8.4 (including)
Connect_secure Ivanti 9.1-r9 (including) 9.1-r9 (including)
Connect_secure Ivanti 9.1-r9.1 (including) 9.1-r9.1 (including)
Connect_secure Ivanti 9.1-r9.2 (including) 9.1-r9.2 (including)

Extended Description

The use of previously-freed memory can have any number of adverse consequences, ranging from the corruption of valid data to the execution of arbitrary code, depending on the instantiation and timing of the flaw. The simplest way data corruption may occur involves the system’s reuse of the freed memory. Use-after-free errors have two common and sometimes overlapping causes:

In this scenario, the memory in question is allocated to another pointer validly at some point after it has been freed. The original pointer to the freed memory is used again and points to somewhere within the new allocation. As the data is changed, it corrupts the validly used memory; this induces undefined behavior in the process. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap data. If one of these function pointers is overwritten with an address to valid shellcode, execution of arbitrary code can be achieved.

Potential Mitigations

References