Crucial Barracuda 0-Day Exploit: Backdoor Networks for 8 Months

A important vulnerability patched 10 days in the past in broadly used e-mail software program from IT safety firm Barracuda Networks has been beneath lively exploitation since October. The vulnerability has been used to put in a number of items of malware inside giant group networks and steal knowledge, Barracuda mentioned Tuesday.

The software program bug, tracked as CVE-2023-2868, is a distant command injection vulnerability that stems from incomplete enter validation of user-supplied .tar information, that are used to pack or archive a number of information. When file names are formatted in a selected method, an attacker can execute system instructions via the QX operator, a perform within the Perl programming language that handles citation marks. The vulnerability is current within the Barracuda E mail Safety Gateway variations via; Barracuda issued a patch 10 days in the past.

On Tuesday, Barracuda notified clients that CVE-2023-2868 has been beneath lively exploitation since October in assaults that allowed menace actors to put in a number of items of malware to be used in exfiltrating delicate knowledge out of contaminated networks.

“Customers whose home equipment we imagine have been impacted have been notified through the ESG person interface of actions to take,” Tuesday’s discover acknowledged. “Barracuda has additionally reached out to those particular clients. Extra clients could also be recognized in the middle of the investigation.”


Malware recognized thus far consists of packages tracked as Saltwater, Seaside, and Seaspy. Saltwater is a malicious module for the SMTP daemon (bsmtpd) that the Barracuda ESG makes use of. The module comprises backdoor performance that features the power to add or obtain arbitrary information, execute instructions, and supply proxy and tunneling capabilities.

Seaside is an x64 executable in ELF (executable and linkable format), which shops binaries, libraries, and core dumps on disks in Linux and Unix-based methods. It gives a persistence backdoor that poses as a official Barracuda Networks service and establishes itself as a PCAP filter for capturing knowledge packets flowing via a community and performing varied operations. Seaside screens monitoring on port 25, which is used for SMTP-based e-mail.

It may be activated utilizing a “magic packet” that’s recognized solely to the attacker however seems innocuous to all others. Mandiant, the safety agency Barracuda employed to research the assaults, mentioned it discovered code in Seaspy that overlaps with the publicly accessible cd00r backdoor.

Seaside, in the meantime, is a module for the Barracuda SMTP daemon (bsmtpd) that screens instructions, together with SMTP HELO/EHLO to obtain a command and management IP handle and port to determine a reverse shell.

Tuesday’s discover consists of cryptographic hashes, IP addresses, file places, and different indicators of compromise related to the exploit of CVE-2023-2868 and the set up of the malware. Firm officers additionally urged all impacted clients to take the next actions:

  1. Guarantee your ESG equipment is receiving and making use of updates, definitions, and safety patches from Barracuda. Contact Barracuda assist ([email protected]) to validate if the equipment is updated.
  2. Discontinue the usage of the compromised ESG equipment and get in touch with Barracuda assist ([email protected]) to acquire a brand new ESG digital or {hardware} equipment.
  3. Rotate any relevant credentials linked to the ESG equipment:
    o  Any linked LDAP/AD
    o  Barracuda Cloud Management
    o  FTP Server
    o  SMB
    o  Any non-public TLS certificates
  4. Evaluation your community logs for any of the [indicators of compromise] and any unknown IPs. Contact [email protected] if any are recognized.

The Cybersecurity and Infrastructure Safety Company added CVE-2023-2868 to its listing of recognized exploited vulnerabilities on Friday.