Week in review: Sudo local privilege escalation flaws fixed, Google patches actively exploited Chrome

A vulnerability in Cisco Unified Communications Manager (Unified CM) and Cisco Unified Communications Manager Session Management Edition (Unified CM SME) could allow an unauthenticated, remote attacker to log in to an affected device using the root account, which has default, static credentials that cannot be changed or deleted. This vulnerability is due to the presence of static user credentials for the root account that are reserved for use during development. An attacker could exploit this vulnerability by using the account to log in to an affected system. A successful exploit could allow the attacker to log in to the affected system and execute arbitrary commands as the root user.

Sudo before 1.9.17p1, when used with a sudoers file that specifies a host that is neither the current host nor ALL, allows listed users to execute commands on unintended machines.

Sudo before 1.9.17p1 mishandles the --chroot option: when sudo runs chrooted, it loads /etc/nsswitch.conf from the user-controlled chroot directory rather than the trusted system copy. A local user who can invoke sudo with --chroot can plant a crafted nsswitch.conf (and the NSS libraries it references) in that directory, causing sudo to load untrusted functionality as root. Successful exploitation grants full root privileges on the host, and any Linux deployment running an unpatched sudo is affected, including Ubuntu, Debian, Red Hat Enterprise Linux, SUSE and openSUSE products per the CPE data. The vulnerability is confirmed exploited in the wild: CISA added it to the Known Exploited Vulnerabilities catalog on 2025-09-29 (ransomware association not yet reported), and EPSS assigns a high 59.4% probability of exploitation within 30 days. Public proof-of-concept references are already available from the researchers who disclosed the flaw.

Do: Upgrade Sudo to 1.9.17p1 or later, or apply your distribution's updated sudo packages (Ubuntu, Debian, Red Hat Enterprise Linux, SUSE and openSUSE have issued patches); the same update also fixes the related local privilege escalation CVE-2025-32462. Until patched, remove or restrict the -R/--chroot option in sudoers policies and identify local users permitted to run sudo with chroot, and audit installed sudo versions across servers and container images. Federal agencies must satisfy the CISA KEV required action, including applicable BOD 22-01 guidance for cloud services.

Improper access control on the NetScaler Management Interface in NetScaler ADC and NetScaler Gateway

Citrix NetScaler ADC and NetScaler Gateway contain an out-of-bounds read (CWE-125) caused by insufficient input validation, which can cause the appliance to read beyond the intended memory buffer (a memory overread). The flaw is only triggerable when the appliance is configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, or RDP Proxy) or as an AAA virtual server, so attackers who can reach those services can potentially induce the overread and obtain sensitive memory contents. Such disclosure could aid follow-on compromise, for example by exposing session or authentication data, and CISA notes known ransomware use. Organizations running NetScaler ADC or NetScaler Gateway in the affected Gateway/AAA configurations are exposed. The vulnerability was added to CISA's Known Exploited Vulnerabilities catalog on 2025-07-10 with known ransomware use and an EPSS of 100% (100th percentile), indicating active exploitation, while no public PoC is known and a CVSS score has not yet been assigned.

Do: Apply the fixed NetScaler ADC/Gateway builds per Citrix's security advisory (exact affected/fixed version ranges are not in the available data, so consult the bulletin); per CISA KEV, apply vendor mitigations, follow BOD 22-01 guidance for cloud services, or discontinue use if mitigations are unavailable. Inventory appliances for Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server configurations, since unconfigured/other deployments are not triggerable. After patching, terminate active and idle VPN sessions and hunt for anomalous access, given the known ransomware exploitation and the information-disclosure nature of the flaw.

Citrix NetScaler ADC and NetScaler Gateway appliances contain a memory buffer overflow (CWE-119) that can lead to unintended control flow and denial of service. The flaw is only reachable when the appliance is configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, or RDP Proxy) or as an AAA virtual server, and it is network-exploitable without authentication or user interaction, though attack complexity is rated high. A successful attacker could achieve unintended control flow — with the CVSS 4.0 vector rating impact high across confidentiality, integrity, and availability — or crash the appliance, disrupting VPN access and application delivery. Any organization running NetScaler ADC or NetScaler Gateway in an affected Gateway/AAA configuration is exposed, a population that public scan data places in the tens of thousands of internet-exposed devices. The vulnerability was added to CISA's KEV catalog on 2025-06-30, confirming exploitation in the wild, with EPSS at 10.1% and no public proof-of-concept known.

Do: Apply the patched NetScaler release specified in Citrix's security bulletin for CVE-2025-6543 immediately, prioritizing appliances in Gateway or AAA configurations, per CISA KEV and BOD 22-01 requirements. Audit which virtual servers (VPN, ICA Proxy, CVPN, RDP Proxy, AAA) are in use and whether they are internet-exposed, and check appliances for signs of compromise before and after upgrading.

CVE-2025-6554 is a type confusion vulnerability (CWE-843) in the V8 JavaScript engine of Google Chrome, affecting versions prior to 138.0.7204.96. A remote attacker can trigger it by inducing a user to open a crafted HTML page, and the flaw permits arbitrary read and write within the browser renderer process. Successful exploitation yields high confidentiality and integrity impact, and V8 type confusion bugs are commonly used as the first stage toward a full browser compromise. Any user of an unpatched Chrome or Chromium-based browser is exposed, and the flaw is being actively exploited in the wild as a zero-day; CISA added it to the Known Exploited Vulnerabilities catalog on 2025-07-02. Ransomware usage is not confirmed (reported as unknown), and no public proof-of-concept is known.

Do: Update Chrome to 138.0.7204.96 or later (check chrome://settings/help) and restart the browser to load the patched V8; users of Chromium-derived browsers (Edge, Brave, Opera, etc.) should install their vendor's corresponding V8 patch. Organizations must apply vendor mitigations or follow BOD 22-01 guidance given the KEV listing, and should inventory managed browsers and force-update policies to confirm rollout.