Salt Typhoon used custom malware JumbledPath to spy on U.S. telecom providers
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2018-0171 | Unauthenticated RCE/DoS in Cisco IOS & IOS XE Smart Install CVE-2018-0171 is a critical (CVSS 9.8) buffer-overflow vulnerability in the Smart Install feature of Cisco IOS and Cisco IOS XE, caused by improper validation of packet data (CWE-20, CWE-787). An unauthenticated, remote attacker can trigger it by simply sending a crafted Smart Install message to TCP port 4786 on an affected device, with no credentials or user interaction required. A successful exploit can cause a device reload, an indefinite loop that triggers a watchdog crash, or arbitrary code execution, giving the attacker full control of the switch or router. Any IOS or IOS XE device running the Smart Install service is affected — a configuration commonly present on Catalyst switches — and devices exposed to the internet on TCP 4786 are at direct risk. Exploitation is confirmed in the wild: the flaw is on CISA's Known Exploited Vulnerabilities catalog, and both Russian (Static Tundra, FSB-linked) and Chinese (Salt Typhoon) state-sponsored actors have exploited it to compromise unpatched, often end-of-life, Cisco network devices at hundreds of organizations worldwide. Do: Upgrade IOS/IOS XE to a fixed release per Cisco's advisory (Bug ID CSCvg76186); for end-of-life hardware that cannot be patched, plan replacement given active nation-state targeting of unpatched devices. If Smart Install is not in use, disable it with 'no vstack'; otherwise restrict TCP port 4786 with ACLs to trusted management hosts. Audit internet-facing switches and routers for Smart Install enabled and TCP 4786 exposed, and prioritize those devices for remediation. | 9.8 | 99% | KEV |
| mass≈250,000+ internet-exposed devices with TCP/4786 open, on top of a multi-million-device IOS/IOS XE installed base | |
| CVE-2023-20198 | Unauthenticated Privilege Escalation in Cisco IOS XE Web UI (Actively Exploited) CVE-2023-20198 is a critical (CVSS 10.0) unauthenticated privilege escalation flaw in the web UI of Cisco IOS XE software, triggered by sending crafted network requests to the exposed web management interface. An attacker with no credentials can use the flaw to gain initial access and issue a privilege 15 command, creating a local user with normal login access; the attacker then chained CVE-2023-20273 (CVSS 7.2) to elevate that account to root and write an implant to the file system. Successful exploitation yields full administrative control of the device, including persistence via the planted implant, on Cisco IOS XE devices with the web UI enabled and reachable from the internet or untrusted networks, including Rockwell Automation Allen-Bradley Stratix 5200 and 5800 switches running IOS XE. Exploitation is confirmed in the wild: the flaw was added to CISA's KEV on 2023-10-16 with a BOD 23-02 directive, EPSS stands at 99.6% (100th percentile), and ongoing campaigns (including the 'BADCANDY' activity flagged by Australia's ASD and Cisco-related telecom intrusions attributed to Salt Typhoon) have been reported. Do: Upgrade affected devices to the fixed releases listed in Cisco's advisory (use Cisco's Software Checker) and, as immediate mitigation, disable the web UI or restrict it to trusted networks/addresses only. Check for compromise by looking for unexpected local user accounts and the implant artifacts Cisco identified (unexpected cisco_tac_alarm.log and cisco_tac.log files in /tmp or /usr/binos/conf), and immediately report positive findings to CISA per BOD 23-02. Keep in mind that patching alone does not remove a root implant, so devices with evidence of compromise should be reimaged or otherwise cleaned per vendor instructions. | 10.0 | 100% | KEV |
| large≈40,000–50,000 internet-exposed IOS XE devices at the time of disclosure (public scan data), within an IOS XE install base in the millions | |
| CVE-2023-20273 | Authenticated Command Injection (Root) in Cisco IOS XE Web UI CVE-2023-20273 is an OS command injection flaw (CWE-78) in the web UI feature of Cisco IOS XE Software, caused by insufficient input validation. An authenticated, remote attacker triggers it by sending crafted input to the web UI, and a successful exploit injects commands that run on the underlying operating system with root privileges, yielding full device compromise (in the October 2023 mass-exploitation campaign it was typically chained with the unauthenticated CVE-2023-20198 to obtain initial access and install a persistent implant). Any Cisco IOS XE device with the web UI enabled and reachable from the internet or an untrusted network is affected; this data does not specify the affected release ranges, which are enumerated in Cisco's advisory. Exploitation is confirmed in the wild: CISA added the flaw to the KEV on 2023-10-23 with BOD 23-02 response actions, EPSS is ~90% (100th percentile), and IOS XE edge devices remain recurring targets of Chinese-nexus espionage campaigns (e.g., Salt Typhoon activity against telecoms). Do: Upgrade affected devices to a fixed IOS XE release per Cisco's advisory; as an interim mitigation, disable the HTTP/HTTPS server (ip http server / ip https server) or restrict Web UI access to trusted hosts only. Per BOD 23-02, hunt for compromise on any exposed device — check for unexpected level-15 local accounts and the implant.lua backdoor in flash memory — and immediately report positive findings to CISA. | 7.2 | 90% | KEV |
| mass≈100,000+ internet-exposed IOS XE devices (public scans observed ~40,000+ compromised within days of disclosure) |
Full article937 words · extracted from securityaffairs.com · click to collapse
Pierluigi Paganini
February 20, 2025
China-linked cyber espionage group Salt Typhoon uses custom malware JumbledPath to on spy U.S. telecom providers.
Cisco Talos researchers reported that China-linked APT group Salt Typhoon uses a custom-built utility, dubbed JumbledPath, to spy on network traffic of U.S. telecommunication providers. China-linked APT group Salt Typhoon (also known as FamousSparrow and GhostEmperor) and has been active since at least 2019 and targeted government entities and telecom companies.
The China-linked APT group is still targeting telecommunications providers worldwide, and according to a report recently published by Recorded Future’s Insikt Group, the threat actors has breached more U.S. telecommunications providers by exploiting unpatched Cisco IOS XE network devices.
Insikt Group researchers reported that the Chinese hacked have exploited two Cisco flaws, tracked as CVE-2023-20198 and CVE-2023-20273.
Insikt researchers reported that ongoing attacks have breached multiple telecom networks, including ISPs in the U.S. and Italy, a U.K.-affiliated U.S. telecom, and providers in South Africa and Thailand.
“Using internet scanning data, Insikt Group identified more than 12,000 Cisco network devices with their web UIs exposed to the internet.” reads the report published by Insikt. “Although over 1,000 Cisco devices were targeted, Insikt Group assesses that this activity was likely focussed, given that this number only represents 8% of the exposed devices and that RedMike engaged in periodic reconnaissance activity, selecting devices linked to telecommunications providers.”
RedMike used generic routing encapsulation (GRE) tunnels on compromised Cisco devices to maintain persistence, evade detection, and stealthily exfiltrate data by encapsulating it within GRE packets.
Cisco Talos researchers now report that Salt Typhoon breached major U.S. telecom firms for over three years, mainly using stolen credentials, with limited vulnerability exploitation.
Cisco states that only in one instance, the APT group exploited a new flaw in its products, the vulnerability CVE-2018-0171. The vulnerability affects the Smart Install feature of Cisco IOS Software and Cisco IOS XE Software, it could be exploited by an unauthenticated, remote attacker to cause a reload of a vulnerable device or to execute arbitrary code on an affected device.
“No new Cisco vulnerabilities were discovered during this campaign. While there have been some reports that Salt Typhoon is abusing three other known Cisco vulnerabilities, we have not identified any evidence to confirm these claims.” reads the report published by Cisco Talos.” Note that each of these CVEs have security fixes available. Threat actors regularly use publicly available malicious tooling to exploit these vulnerabilities, making patching of these vulnerabilities imperative.”
Cisco reported that Salt Typhoon used stolen credentials, captured network configs, and intercepted SNMP, TACACS, and RADIUS traffic to gather more credentials for further access. However, it is still unclear how the group obtained the credentials employed in the attacks.
The group exfiltrated device configs via TFTP/FTP, exposing weakly encrypted passwords, SNMP credentials, and network details for further reconnaissance. The threat actors relied on machine-to-machine pivoting to perform lateral movement inside the telecom networks.
“The threat actor also pivoted from a compromised device operated by one telecom to target a device in another telecom. We believe that the device associated with the initial telecom was merely used as a hop point and not the intended final target in several instances.” continues the report. “Some of these hop points were also used as a first hop for outbound data exfiltration operations. Much of this pivoting included the use of network equipment from a variety of different manufacturers.”
The attackers manipulated network settings by enabling Guest Shell for command execution, modifying access control lists (ACLs), and creating stealthy hidden accounts.
Salt Typhoon used the JumbledPath tool to remotely capture packets via jump-hosts, clear logs, and exfiltrate encrypted data.
JumbledPath is written in GO and compiled as an ELF binary using an x86-64 architecture to use the utility on Linux operating systems.
The threat actor attempted to evade detection by altering loopback addresses to bypass ACLs, clearing logs to hide activity, disabling Guest Shell, and modifying AAA settings for unauthorized access.
The report includes Indicators of Compromise (IOCs) for this campaign along with recommendations to mitigate the Salt Typhoon attacks.
In mid-December 2024, the researchers also spotted the Salt Typhoon group performing reconnaissance against multiple infrastructure assets operated by a Myanmar-based telecommunications provider, Mytel.
In January, The Wall Street Journal reported that the China-linked cyberespionage group Salt Typhoon targeted more US telecoms than previously known.
According to WSJ, which cited people familiar with the matter, the Chinese cyberspies also compromised Charter Communications and Windstream. The threat actors exploited vulnerabilities in network devices from security major vendor, including Cisco and Fortinet.
At the end of December 2024, a White House official confirmed that China-linked APT group Salt Typhoon has breached a ninth U.S. telecoms company as part of a cyberespionage campaign aimed at telco firms worldwide.
In early December 2024, President Biden’s deputy national security adviser Anne Neuberger said that China-linked APT group Salt Typhoon had breached telecommunications companies in dozens of countries.
The Wall Street Journal reported that the senior White House official revealed that at least eight U.S. telecommunications firms were compromised in the attack.
The Salt Typhoon hacking campaign, active for 1–2 years, has targeted telecommunications providers in several dozen countries, according to a U.S. official.
In December, Lumen announced that the Salt Typhoon APT group, was locked out of its network, TechCrunch reported. The company added that it is not aware of a data breach.
In December, US carriers AT&T and Verizon also reported they had secured their networks after cyberespionage attempts by the China-linked Salt Typhoon group.
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(SecurityAffairs – hacking, China)
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