Cisco alerts customers to second actively exploited zero-day in as many days

CVE-2025-20281 is an injection flaw (CWE-74) in a specific API of Cisco Identity Services Engine (ISE) and Cisco ISE Passive Identity Connector (ISE-PIC), caused by insufficient validation of user-supplied input. An unauthenticated, remote attacker can trigger it by sending a crafted request to that API; no valid credentials or user interaction are required. A successful exploit yields arbitrary code execution on the underlying operating system with root privileges, giving the attacker full control of the affected device (scope-changing per the CVSS 10.0 score). Any organization running affected ISE or ISE-PIC releases is exposed, particularly where the vulnerable API is reachable from untrusted networks. The flaw is confirmed under active exploitation: CISA added it to the Known Exploited Vulnerabilities catalog on 2025-07-28, EPSS assigns a 97.1% probability of exploitation within 30 days, and ZDI has published a writeup of the unauthenticated root RCE.

Do: Upgrade Cisco ISE and ISE-PIC to the patched releases specified in Cisco's PSIRT advisory, and check whether the vulnerable API/admin interface is reachable from untrusted networks, restricting access until patching is complete. As a KEV entry added 2025-07-28, U.S. federal agencies must apply vendor mitigations per BOD 22-01 guidance or discontinue use of the product; given EPSS of 97.1% and confirmed active exploitation, prioritize internet-facing ISE instances and review API/web-server logs for signs of exploitation.

CVE-2025-20337 is a critical (CVSS 3.1: 10.0) injection vulnerability (CWE-74) in a specific API of Cisco Identity Services Engine (ISE) and Cisco ISE Passive Identity Connector (ISE-PIC), caused by insufficient validation of user-supplied input. An unauthenticated, remote attacker can trigger it by submitting a crafted request to the affected API, with no valid credentials required. Successful exploitation allows arbitrary code execution on the underlying operating system with root privileges, giving the attacker full control of the affected device, consistent with the changed-scope, high-impact CVSS score. Any organization running Cisco ISE or ISE-PIC is potentially affected; CISA added the flaw to the Known Exploited Vulnerabilities catalog on 2025-07-28, and press reports indicate active exploitation, including zero-day use per Amazon threat intelligence coverage. EPSS assigns a 67% probability of exploitation within 30 days (99th percentile), and no public proof-of-concept is known.

Do: Upgrade Cisco ISE and ISE-PIC to the fixed releases identified in Cisco's security advisory (fixed version details are not included in this data set), and check management/API logs for unauthenticated crafted API requests indicating exploitation. As an interim mitigation, restrict network access to the affected API and the ISE administration interface. Organizations covered by BOD 22-01 must apply vendor mitigations per Cisco's instructions or discontinue use of the product by the KEV remediation deadline.

Cisco Identity Services Engine (ISE) and the Cisco ISE Passive Identity Connector (ISE-PIC) contain an incorrect use of privileged APIs flaw (CWE-648) affecting the web-based management interface. An unauthenticated, remote attacker with network access to that interface can send requests that invoke privileged APIs without authenticating, bypassing the interface's access controls. Successful exploitation grants the attacker unauthorized access to the affected device, presumably with the administrative capabilities available through the management interface, such as control over network access policy and visibility into identity data. Any organization running an affected Cisco ISE or ISE-PIC release is potentially affected, with risk highest where the management interface is reachable from untrusted networks. The flaw was added to CISA's Known Exploited Vulnerabilities catalog on 2026-09-16, indicating exploitation in the wild, though no public proof-of-concept is known and CVSS scoring is pending.

Do: Upgrade ISE and ISE-PIC to the fixed releases specified in Cisco's security advisory (fixed versions are not provided in the available data); because the flaw is on CISA's KEV list, federal agencies must patch or apply mitigations per BOD 26-04 timelines. Until patched, restrict access to the web-based management interface to trusted administrative networks only, verify no unintended exposure via firewalls/ACLs, and monitor for unauthenticated access attempts against the interface.

Cisco AsyncOS Software for Cisco Secure Email Gateway contains a SQL injection flaw (CWE-89) in its email parsing logic, caused by insufficient validation of message content. An unauthenticated, remote attacker can trigger it simply by sending a crafted email containing malicious SQL statements through an affected gateway, with no user interaction required. Successful exploitation allows arbitrary SQL execution that escalates to arbitrary operating-system command execution with root privileges, fully compromising the appliance and all mail flowing through it. Any organization running an affected version of Cisco Secure Email Gateway is impacted, and because these appliances sit on the inbound mail path they are inherently reachable over the network. There is no known public proof-of-concept, the flaw is not on the CISA KEV list, and no in-the-wild exploitation has been reported to date, though the CVSS 9.8 rating makes patching urgent.

Do: Upgrade to the fixed AsyncOS release listed in the corresponding Cisco PSIRT advisory as soon as possible, since the flaw is unauthenticated, requires no user interaction, and yields root. Until patched, apply any Cisco-documented workarounds and tightly restrict which hosts can submit mail to the gateway where operationally feasible. Review mail and system logs on these appliances for anomalies such as SQL errors in parsing, unexpected processes, or unexplained outbound connections that could indicate exploitation attempts.