Cisco Confirms Salt Typhoon Exploited CVE-2018
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 article584 words · extracted from thehackernews.com · click to collapse
Ravie LakshmananFeb 21, 2025Network Security / Vulnerability
Cisco has confirmed that a Chinese threat actor known as Salt Typhoon gained access by likely abusing a known security flaw tracked as CVE-2018-0171, and by obtaining legitimate victim login credentials as part of a targeted campaign aimed at major U.S. telecommunications companies.
"The threat actor then demonstrated their ability to persist in target environments across equipment from multiple vendors for extended periods, maintaining access in one instance for over three years," Cisco Talos said, describing the hackers as highly sophisticated and well-funded.
"The long timeline of this campaign suggests a high degree of coordination, planning, and patience — standard hallmarks of advanced persistent threat (APT) and state-sponsored actors."
The networking equipment major said it found no evidence that other known security bugs have been weaponized by the hacking crew, contrary to a recent report from Recorded Future that revealed exploitation attempts involving flaws tracked as CVE-2023-20198 and CVE-2023-20273 to infiltrate networks.
An important aspect of the campaign is the use of valid, stolen credentials to gain initial access, although the manner in which they are acquired is unknown at this stage. The threat actor has also been observed making efforts to get hold of credentials via network device configurations and deciphering local accounts with weak password types.
"In addition, we have observed the threat actor capturing SNMP, TACACS, and RADIUS traffic, including the secret keys used between network devices and TACACS/RADIUS servers," Talos noted. "The intent of this traffic capture is almost certainly to enumerate additional credential details for follow-on use."
Another noteworthy behavior exhibited by Salt Typhoon entails leveraging living-off-the-land (LOTL) techniques on network devices, abusing the trusted infrastructure as pivot points to jump from one telecom to another.
It's suspected that these devices are being used as intermediate relays to reach the intended final target or as a first hop for outbound data exfiltration operations, as it offers a way for the adversary to remain undetected for extended periods of time.
Furthermore, Salt Typhoon has been spotted altering network configurations to create local accounts, enable Guest Shell access, and facilitate remote access via SSH. Also put to use is a bespoke utility named JumbledPath that allows them to execute a packet capture on a remote Cisco device through an actor-defined jump-host.
The Go-based ELF binary is also capable of clearing logs and disabling logging in an attempt to obfuscate traces of the malicious activity and make forensic analysis more difficult. This is supplemented by periodic steps undertaken to erase relevant logs, including .bash_history, auth.log, lastlog, wtmp, and btmp, where applicable.
"The use of this utility would help to obfuscate the original source, and ultimate destination, of the request and would also allow its operator to move through potentially otherwise non-publicly-reachable (or routable) devices or infrastructure," Cisco noted.
"The threat actor repeatedly modified the address of the loopback interface on a compromised switch and used that interface as the source of SSH connections to additional devices within the target environment, allowing them to effectively bypass access control lists (ACLs) in place on those devices."
The company said it also identified "additional pervasive targeting" of Cisco devices with exposed Smart Install (SMI), followed by the exploitation of CVE-2018-0171. The activity, it pointed out, is unrelated to Salt Typhoon and does not share overlaps with any known threat actor or group.
Found this article interesting? Follow us on Google News, Twitter and LinkedIn to read more exclusive content we post.
Text extracted automatically; images, tables and formatting may be missing. Original: https://thehackernews.com/2025/02/cisco-confirms-salt-typhoon-exploited.html