Cisco is urging customers to update its Firepower Management Center software, after users informed it of a critical bug that attackers could exploit over the internet.
Like many Cisco bugs, the flaw was found in the web-based management interface of its software. The bug has a severity rating of 9.8 out of a possible 10 and means admins should patch sooner rather than later.
The vulnerability is caused by a glitch in the way Cisco's software handles Lightweight Directory Access Protocol (LDAP) authentication responses from an external authentication server. Remote attackers could exploit the flaw by sending specially crafted HTTP requests to the device.
Devices are vulnerable if they've been configured to authenticate users of the web interface through an external LDAP server. The networking company recommends that admins go to System > Users > External Authentication to see whether it's been configured for external LDAP authentication.
How customers should remediate the issue will depend on which release of Firepower Management Center (FMC) they're running. There is no workaround, but hotfix patches are available for several new releases of FMC, and maintenance releases that address the flaw are scheduled for later this year.
"Customers may install a fix either by upgrading to a fixed release or by installing a hotfix patch," Cisco notes.
Cisco recommends that customers on FMC earlier than 6.1.0 – which is no longer supported – migrate to a supported version. However, there is a hotfix available.
Customers on 6.2.0, 6.2.1, and 6.2.2 should migrate to a new version, such as FMC release 6.2.3, which has a patch available and will see a maintenance release in February, while a maintenance release is coming for systems on release 6.3.0 in May 2020. Release 6.3.0 also has a patch available now.
Customers on FMC release 6.4.0 need to apply patches or upgrade to release 220.127.116.11, while customers on FMC 6.5.0 need to upgrade to 18.104.22.168.
Cisco is recommending that customers on releases earlier than 6.1.0 move to 6.2.3 and apply the patches. Those on 6.1.0 should apply the hotfix or move to 6.2.3 and then apply the hotfix.
It also notes that this critical bug doesn't affect Cisco Adaptive Security Appliance (ASA) Software or Cisco Firepower Threat Defense Software.
Cisco also disclosed seven high-severity flaws and 19 medium-severity security issues.
This FMC critical flaw follows updates made available earlier this month for three critical flaws affecting Cisco's Data Center Network Manager (DCNM) software.
The researcher who reported the flaw has released proof-of-concept exploit code, but Cisco says it is not aware of any malicious use of the flaws.