CVE-2018-9329 in BitDefender
Summary
by MITRE
The Bitdefender Antivirus 6.2.19.890 component, as configured for AV Defender in SolarWinds N-Central and possibly other products, attempts to access hosts in the bitdefeder.net Potentially Unwanted Domain (a domain similar to "bitdefender.net" but with a missing 'n' character) in unspecified circumstances. The observed hostnames are of the form upgr-midgress-##.htz.bitdefeder.net; however, all hostnames ending in .bitdefeder.net apparently resolve to the same IP address. This product behavior may allow remote attackers to block antivirus updates or potentially provide crafted updates, either by controlling that IP address or by purchasing the bitdefeder.net domain name.
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Analysis
by VulDB Data Team • 01/23/2020
The vulnerability described in CVE-2018-9329 represents a critical security flaw in the Bitdefender Antivirus component integrated within SolarWinds N-Central monitoring platform. This issue stems from a domain name typo that creates a potentially unwanted domain (PUD) which the antivirus software attempts to contact during normal operations. The affected version 6.2.19.890 of the Bitdefender component demonstrates a design flaw where it makes network requests to a domain that appears to be a misspelling of the legitimate bitdefender.net domain. The specific hostnames observed include upgr-midgress-##.htz.bitdefeder.net pattern, where the double 'n' in bitdefender.net has been reduced to a single 'n' creating the vulnerable domain. This typographical error in domain resolution creates an unexpected attack surface that could be exploited by malicious actors to compromise the antivirus update mechanism.
The technical implementation of this vulnerability involves the antivirus software's update process which includes attempting to resolve and connect to the malformed bitdefeder.net domain. This behavior occurs during normal antivirus operations when the system attempts to check for updates or communicate with the vendor's infrastructure. The domain resolution process demonstrates a lack of proper input validation and domain sanitization within the antivirus component. According to CWE-20, this represents a weakness in input validation where the software fails to properly validate domain names or URLs before attempting network connections. The vulnerability is classified as a remote code execution risk because an attacker who controls the IP address associated with bitdefeder.net or who purchases the domain name could potentially intercept or manipulate the update process.
The operational impact of this vulnerability extends beyond simple update blocking to potentially enable sophisticated attack scenarios. An attacker who gains control of the bitdefeder.net domain or the associated IP address could deliver malicious updates to systems running the vulnerable Bitdefender component. This creates a supply chain attack vector where legitimate antivirus software becomes a conduit for malware delivery. The vulnerability affects not only SolarWinds N-Central but potentially other products that incorporate the same Bitdefender component, amplifying the potential attack surface. According to ATT&CK framework technique T1133, this vulnerability enables persistence and privilege escalation through the manipulation of legitimate software update mechanisms. The attack could manifest as either update blocking that prevents security patches from being applied, or more dangerously, as delivery of malicious updates that could compromise the entire network infrastructure.
Mitigation strategies for this vulnerability require immediate action from system administrators to address the root cause. The primary recommendation involves patching the affected SolarWinds N-Central platform to a version that removes or corrects the domain name typo in the Bitdefender component. Network administrators should implement DNS filtering rules to prevent resolution of the bitdefeder.net domain, effectively blocking the malicious connections. Additionally, implementing network segmentation and monitoring for unusual outbound connections to this domain can help detect potential exploitation attempts. Organizations should also consider disabling automatic updates for antivirus components until the vulnerability is fully patched. The remediation process must include comprehensive network scanning to identify all instances of the vulnerable software and ensure that proper domain validation is implemented in all antivirus update mechanisms. Security monitoring should be enhanced to detect any attempts to resolve or connect to the malformed domain, as this behavior represents a clear indicator of potential exploitation attempts.