CVE-2021-39113: 
JIRA vulnerability analysis and mitigation

Atlassian Jira Server and Data Center were affected by a Broken Access Control vulnerability (CVE-2021-39113) that was discovered in August 2021. The vulnerability allowed anonymous remote attackers to continue viewing cached content even after losing permissions through the allowlist feature. The affected versions include Jira installations before version 8.13.9, and versions from 8.14.0 to before 8.18.0 (NVD, CVE).

The vulnerability received a CVSS v3.1 base score of 7.5 (HIGH), with a vector string of CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. This indicates that the vulnerability can be exploited over the network, requires low attack complexity, needs no privileges or user interaction, and primarily impacts confidentiality. The vulnerability is classified under CWE-613 (Insufficient Session Expiration) (NVD).

The primary impact of this vulnerability is unauthorized access to cached content. Even after permissions are revoked, anonymous attackers could continue to view cached content that they should no longer have access to, representing a significant confidentiality breach (NVD).

Atlassian addressed this vulnerability by releasing fixed versions 8.13.9 and 8.18.0. Users running affected versions should upgrade to these patched versions to mitigate the vulnerability (Atlassian Advisory).