Security
Headlines
HeadlinesLatestCVEs

Headline

Update your PaperCut application servers now: Exploits in the wild

Categories: News Tags: PaperCut

Tags: server

Tags: exploit

Tags: attack

Tags: authentication

Tags: update

Tags: patch

We take a look at urgent updates needed for users of PaperCut, after two exploits were found in the wild.

(Read more…)

The post Update your PaperCut application servers now: Exploits in the wild appeared first on Malwarebytes Labs.

Malwarebytes
#vulnerability#web#git#auth

PaperCut, maker of print management solutions, has urged product users to update as soon as possible. A security vulnerability which exploits unpatched servers has been seen in the wild, with serious ramifications for any organisation impacted.

Two specific vulnerabilities are at the heart of this alert, and are ranked with severity scores of 9.8 (critical) and 8.2 (high) respectively. Full information about the individual security flaws has not been revealed, in order to reduce the likelihood of more attackers making use of them.

Mitigation

At time of writing, both security issues have been addressed with patches. If you update your PaperCut application servers, you are no longer at risk. A recent check in security tool Shodan’s search functionality highlights roughly 1,700 software instances currently exposed to the internet. These flaws are quite severe, so it’s absolutely worth your time to get things updated as soon as possible.

From the Updating FAQ:

  • Please follow your usual upgrade procedure. Additional links on the ‘Check for updates’ page (accessed through the Admin interface > About > Version info > Check for updates) will allow customers to download fixes for previous major versions which are still supported (e.g. 20.1.7 and 21.2.11) as well as the current version available.
  • If you are using PaperCut MF, we highly recommend following your regular upgrade process. Your PaperCut partner or reseller information can also be found on the ‘About’ tab in the PaperCut admin interface.

If you’re unable to upgrade

PaperCut advises those who are unable to apply the patches to follow the below steps:

  • Block all inbound traffic from external IPs to the web management port (port 9191 and 9192 by default)
  • Block all traffic inbound to the web management portal on the firewall to the server. Note: this will prevent lateral movement from internal hosts but management of the PaperCut service can only be performed on that asset.
  • Apply “Allow list” restrictions under Options > Advanced > Security > Allowed site server IP addresses. Set this to only allow the IP addresses of verified Site Servers on your network. Note this only addresses ZDI-CAN-19226 / PO-1219.

Exploits

The two exploits in question are:

CVE-2023-27350: This vulnerability allows remote attackers to bypass authentication on affected installations of PaperCut NG 22.0.5 (Build 63914). Authentication is not required to exploit this vulnerability.

CVE-2023-27351: This vulnerability allows remote attackers to bypass authentication on affected installations of PaperCut NG 22.0.5 (Build 63914). Authentication is not required to exploit this vulnerability. The issue results from improper implementation of the authentication algorithm. An attacker can leverage this vulnerability to bypass authentication on the system.

In both cases, compromised systems could be used to perform additional exploitation after the initial attack. Arbitrary code can be deployed, or even ransomware if that’s part of the attacker’s toolkit. The relative ease with which these exploits can be launched is just one reason for the high threat severity score. Indeed, researchers quickly discovered two types of (legitimate) remote management software being used in these attacks. These management tools are used to grant a potential form of persistent remote access to the target network. From here, they can burrow in ever deeper without the affected organisation noticing.

It will probably be a while before all possible patchable installations are running the necessary updates. If you’re potentially affected, do your part and head over to the updates page immediately.

Malwarebytes removes all remnants of ransomware and prevents you from getting reinfected. Want to learn more about how we can help protect your business? Get a free trial below.

TRY NOW

Related news

CVE-2023-39143: CVE-2023-39143: PaperCut Path Traversal/File Upload RCE Vulnerability

PaperCut NG and PaperCut MF before 22.1.3 on Windows allow path traversal, enabling attackers to upload, read, or delete arbitrary files. This leads to remote code execution when external device integration is enabled (a very common configuration).

PaperCut PaperCutNG Authentication Bypass

This Metasploit module leverages an authentication bypass in PaperCut NG. If necessary it updates Papercut configuration options, specifically the print-and-de vice.script.enabled and print.script.sandboxed options to allow for arbitrary code execution running in the builtin RhinoJS engine. This module logs at most 2 events in the application log of papercut. Each event is tied to modification of server settings.

Buhti Ransomware Gang Switches Tactics, Utilizes Leaked LockBit and Babuk Code

The threat actors behind the nascent Buhti ransomware have eschewed their custom payload in favor of leaked LockBit and Babuk ransomware families to strike Windows and Linux systems. "While the group doesn't develop its own ransomware, it does utilize what appears to be one custom-developed tool, an information stealer designed to search for and archive specified file types," Symantec said in a

Bl00dy Ransomware Gang Strikes Education Sector with Critical PaperCut Vulnerability

U.S. cybersecurity and intelligence agencies have warned of attacks carried out by a threat actor known as the Bl00dy Ransomware Gang that attempt to exploit vulnerable PaperCut servers against the education facilities sector in the country. The attacks took place in early May 2023, the Federal Bureau of Investigation (FBI) and Cybersecurity and Infrastructure Security Agency (CISA) said in a

Threat Source newsletter (May 11, 2023) — So much for that ransomware decline

A ransomware attack on the city of Dallas, Texas is still disrupting many social services as of Wednesday, including hampering police communications and operations and potentially putting personal information at risk.

Microsoft reports two Iranian hacking groups exploiting PaperCut flaw

By Deeba Ahmed The two groups exploiting the vulnerability are Mango Sandstorm and Mint Sandstorm. Both are linked to the Iranian government and intelligence agencies. This is a post from HackRead.com Read the original post: Microsoft reports two Iranian hacking groups exploiting PaperCut flaw

Microsoft Warns of State-Sponsored Attacks Exploiting Critical PaperCut Vulnerability

Iranian nation-state groups have now joined financially motivated actors in actively exploiting a critical flaw in PaperCut print management software, Microsoft said. The tech giant's threat intelligence team said it observed both Mango Sandstorm (Mercury) and Mint Sandstorm (Phosphorus) weaponizing CVE-2023-27350 in their operations to achieve initial access. "This activity shows Mint

Ransomware review: May 2023

LockBit maintained its position as the top ransomware attacker and was also observed expanding into the Mac space. (Read more...) The post Ransomware review: May 2023 appeared first on Malwarebytes Labs.

Researchers Uncover New Exploit for PaperCut Vulnerability That Can Bypass Detection

Cybersecurity researchers have found a way to exploit a recently disclosed critical flaw in PaperCut servers in a manner that bypasses all current detections. Tracked as CVE-2023-27350 (CVSS score: 9.8), the issue affects PaperCut MF and NG installations that could be exploited by an unauthenticated attacker to execute arbitrary code with SYSTEM privileges. While the flaw was patched by the

Threat Source newsletter (April 27, 2023) — New Cisco Secure offerings and extra security from Duo

AI-generated spam comments on Amazon, the latest on the 3CX supply chain attack and more security headlines from the past week.

Microsoft Confirms PaperCut Servers Used to Deliver LockBit and Cl0p Ransomware

Microsoft has confirmed that the active exploitation of PaperCut servers is linked to attacks designed to deliver Cl0p and LockBit ransomware families. The tech giant's threat intelligence team is attributing a subset of the intrusions to a financially motivated actor it tracks under the name Lace Tempest (formerly DEV-0950), which overlaps with other hacking groups like FIN11, TA505, and Evil

PaperCut NG/MG 22.0.4 Authentication Bypass

PaperCut NG/MG version 22.0.4 suffers from an authentication bypass vulnerability.

Attackers Abuse PaperCut RCE Flaws to Take Over Enterprise Print Servers

Customers should apply updates to the print management software used by more than 100 million organizations worldwide, with typical US customers found in the SLED sector.

Attackers Abuse PaperCut RCE Flaws to Take Over Enterprise Print Servers

Customers should apply updates to the print management software used by more than 100 million organizations worldwide, with typical US customers found in the SLED sector.

Russian Hackers Suspected in Ongoing Exploitation of Unpatched PaperCut Servers

Print management software provider PaperCut said that it has "evidence to suggest that unpatched servers are being exploited in the wild," citing two vulnerability reports from cybersecurity company Trend Micro. "PaperCut has conducted analysis on all customer reports, and the earliest signature of suspicious activity on a customer server potentially linked to this vulnerability is 14th April 01

CISA Adds 3 Actively Exploited Flaws to KEV Catalog, including Critical PaperCut Bug

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) on Friday added three security flaws to its Known Exploited Vulnerabilities (KEV) catalog, based on evidence of active exploitation. The three vulnerabilities are as follows - CVE-2023-28432 (CVSS score - 7.5) - MinIO Information Disclosure Vulnerability  CVE-2023-27350 (CVSS score - 9.8) - PaperCut MF/NG Improper Access Control

CVE-2023-27351: APRIL 19 UPDATE | PaperCut MF/NG vulnerability bulletin (March 2023)

This vulnerability allows remote attackers to bypass authentication on affected installations of PaperCut NG PaperCut NG 22.0.5 (Build 63914). Authentication is not required to exploit this vulnerability. The specific flaw exists within the SecurityRequestFilter class. The issue results from improper implementation of the authentication algorithm. An attacker can leverage this vulnerability to bypass authentication on the system. Was ZDI-CAN-19226.

Malwarebytes: Latest News

Our Santa wishlist: Stronger identity security for kids