{"id":229129,"date":"2026-03-28T03:07:00","date_gmt":"2026-03-28T07:07:00","guid":{"rendered":"https:\/\/news-you-need.com\/index.php\/2026\/03\/28\/cisa-adds-cve-2025-53521-to-kev-after-active-f5-big-ip-apm-exploitation\/"},"modified":"2026-03-30T06:45:09","modified_gmt":"2026-03-30T10:45:09","slug":"cisa-adds-cve-2025-53521-to-kev-after-active-f5-big-ip-apm-exploitation","status":"publish","type":"post","link":"https:\/\/news-you-need.com\/index.php\/2026\/03\/28\/cisa-adds-cve-2025-53521-to-kev-after-active-f5-big-ip-apm-exploitation\/","title":{"rendered":"CISA Adds CVE-2025-53521 to KEV After Active F5 BIG-IP APM Exploitation"},"content":{"rendered":"<p><a href=\"https:\/\/thehackernews.com\/2026\/03\/cisa-adds-cve-2025-53521-to-kev-after.html\">CISA Adds CVE-2025-53521 to KEV After Active F5 BIG-IP APM Exploitation<\/a><\/p>\n<p><a href=\"https:\/\/thehackernews.com\/2026\/03\/cisa-adds-cve-2025-53521-to-kev-after.html\">https:\/\/thehackernews.com\/2026\/03\/cisa-adds-cve-2025-53521-to-kev-after.html<\/a><\/p>\n<p>Publish Date: <a href=\"publish_date]\">2026-03-28 03:07:00<\/a><\/p>\n<p>Source Domain: <a href=\"thehackernews.com\">thehackernews.com<\/a><\/p>\n<p><span class=\"p-author\">\ue804<span class=\"author\">Ravie Lakshmanan<\/span>\ue802<span class=\"author\">Mar 28, 2026<\/span><\/span><span class=\"p-tags\">Vulnerability \/ Network Security<\/span><\/p>\n<p>The U.S. Cybersecurity and Infrastructure Security Agency (CISA) on Friday added a critical security flaw impacting F5 BIG-IP Access Policy Manager (APM) to its Known Exploited Vulnerabilities (KEV) catalog, citing evidence of active exploitation.<\/p>\n<p>The vulnerability in question is <strong>CVE-2025-53521<\/strong> (CVSS v4 score: 9.3), which could allow a threat actor to achieve remote code execution.<\/p>\n<p>&#8220;When a BIG-IP APM access policy is configured on a virtual server, specific malicious traffic can lead to Remote Code Execution (RCE),&#8221; according to a description of the flaw in CVE.org.<\/p>\n<p>While the shortcoming was initially categorized and remediated as a denial-of-service (DoS) vulnerability with a CVSS v4 score of 8.7, F5 said it has been reclassified as a case of RCE in light of &#8220;new information obtained in March 2026.&#8221;<\/p>\n<p>The company has since updated its advisory to confirm that the vulnerability &#8220;has been exploited in the vulnerable BIG-IP versions.&#8221; It did not share any additional details on who may be behind the exploitation activity.<\/p>\n<p>However, F5 published a number of indicators that can be used to assess if the system has been compromised &#8211;<\/p>\n<ul>\n<li>File-related indicators &#8211;\n<ul>\n<li>Presence of \/run\/bigtlog.pipe and\/or \/run\/bigstart.ltm.<\/li>\n<li>Mismatch of file hashes when compared to known good versions of \/usr\/bin\/umount and\/or \/usr\/sbin\/httpd.<\/li>\n<li>Mismatch of file sizes or timestamps when compared to known good versions of \/usr\/bin\/umount and\/or \/usr\/sbin\/httpd.<\/li>\n<li>Each release and EHF may have different file sizes and timestamps.<\/li>\n<\/ul>\n<\/li>\n<li>Log-related indicators &#8211;\n<ul>\n<li>An entry in &#8220;\/var\/log\/restjavad-audit..log&#8221; showing a local user accessing the iControl REST API from localhost.<\/li>\n<li>An entry in &#8220;\/var\/log\/auditd\/audit.log.&#8221; showing a local user accessing the iControl REST API from localhost to disable SELinux.<\/li>\n<li>Log messages in &#8220;\/var\/log\/audit&#8221; show the results of a command being run in the audit log.<\/li>\n<\/ul>\n<\/li>\n<li>Other TTPs observed include &#8211;\n<ul>\n<li>Modifications to&#8230;<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p><a href=\"https:\/\/thehackernews.com\/2026\/03\/cisa-adds-cve-2025-53521-to-kev-after.html\">Source<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>CISA Adds CVE-2025-53521 to KEV After Active F5 BIG-IP APM Exploitation https:\/\/thehackernews.com\/2026\/03\/cisa-adds-cve-2025-53521-to-kev-after.html Publish Date: 2026-03-28&#8230;<\/p>\n","protected":false},"author":1,"featured_media":229130,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"fifu_image_url":"https:\/\/blogger.googleusercontent.com\/img\/b\/R29vZ2xl\/AVvXsEgOCtHFfd9TZrhTa9APggVpivUkp_7HLw49145Q93B-76BiG0kkbGOPgViPII25Inn9b8710FjsB1sG716DO1Qh3ikSV88oqwdhSCJ7V2FTWgPq1xaA_UqMVwIEi4zmLnAmXQmbdG2fWAVBx6H_OiHqCOzghwBkuQYy4mYUCIdIyBi54ojbF3rc_OGIPlGc\/s16000\/f5.jpg","fifu_image_alt":"","footnotes":""},"categories":[15],"tags":[24,29,34,27],"class_list":["post-229129","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-cybersecurity","tag-cybersecurity","tag-network-security","tag-threat-actor","tag-vulnerability"],"_links":{"self":[{"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/posts\/229129"}],"collection":[{"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/comments?post=229129"}],"version-history":[{"count":1,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/posts\/229129\/revisions"}],"predecessor-version":[{"id":229131,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/posts\/229129\/revisions\/229131"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/media\/229130"}],"wp:attachment":[{"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/media?parent=229129"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/categories?post=229129"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/tags?post=229129"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}