bk99.de entertain the web since 1997

bk99.de
hß · SecurityCurated

Security holes: patches protect Cisco firewalls and switches

Summary

In August 2023 Cisco closed several holes in firewalls and switches. Rated high were an SNMP hole in Firepower 4100 and 9300 through which authenticated attackers could trigger restarts, an IS-IS hole in Nexus 3000 and 9000 without authentication, and a DoS hole in NX-OS. Further medium holes affected, among others, the Application Policy Infrastructure Controller.

Ideas

  • Management protocols such as SNMP are a risk to availability even after authentication.
  • Prepared routing protocol packets can bring down switches.
  • Authentication services such as TACACS+ and RADIUS were also an attack path.

Insights

  • Denial of service on core network components hits all connected services.
  • Routing and management protocols belong on separate, trusted network segments.

Facts

  • The SNMP hole is listed as CVE-2023-20200.
  • The IS-IS hole CVE-2023-20169 could be exploited without authentication.

References

Critique

  • The report is a list of advisories without classifying how exposed the protocols typically are.

Recommendations

  • Restrict SNMP to a management network and use SNMPv3 with authentication.
  • Only accept IS-IS and other routing messages from known neighbours.

Read the original article

Search the Web Archive

hß · 2019

CERT-Bund warns of unpatched holes in Cisco’s Firepower firewall software

In August 2019 CERT-Bund warned of four unpatched holes in Cisco’s Firepower firewall software through which attackers could bypass the filter rules without logging in. While CERT-Bund rated the risk as high, Cisco rated all four holes only as “Medium” with CVSS 5.8. At the time of the report there were neither updates nor workarounds.

hß · 1998

Microsoft patches PPTP security holes

In August 1998 Microsoft released final patches for security holes in its implementation of the Point-to-Point Tunneling Protocol. PPTP was mainly used to build VPNs over the internet; the problems had become known in early June. Security bulletin 98-012 recommended the updates for dial-up networking under Windows 95 and 98 and for RAS under Windows NT 4.0.

hß · 2026

Palo Alto Networks: numerous security holes in Prisma Browser closed

In August 2026 Palo Alto Networks closed numerous holes, most of them in the Chromium-based enterprise browser Prisma Browser. There, memory bugs could lead to code execution; version 150.49.8.187 was fixed. Further holes affected the GlobalProtect VPN client on Android, macOS and Windows, including a privilege escalation (CVE-2026-0299).