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CVE-2019-15271Cisco RV Series Routers Deserialization of Untrusted Data Vulnerability

Patch nowHigh8.8Exploited, CISA due date 2022-06-22EPSS 5.5%, higher than 93% of scored CVEs

CVE-2019-15271 is a deserialization of untrusted data in Cisco RV Series Routers, rated high (8.8 on CVSS 3.1).

Why this priority: Exploited in the wild: listed in CISA's KEV catalog.

Published · Updated · NVD status: Analyzed

What it is

Serialized objects from outside are turned back into live objects, which a crafted payload can abuse to run code.

How it is reached

An attacker can exploit it over the network, with an ordinary user account, and nobody has to click anything.

What an attacker gains

A successful attack can read the data it protects, change data or behaviour and take it offline. In practice, this kind of flaw lets an attacker turn crafted data into code execution inside the receiving service.

Is it being exploited?

CISA added it to the Known Exploited Vulnerabilities catalog on 2022-06-08: it is being exploited in the wild. EPSS estimates a 5.5% chance of exploitation activity in the next 30 days, higher than 93% of scored CVEs.

What to do

  1. Treat it as urgent: it is on CISA's KEV list. CISA's deadline for US federal agencies: 2022-06-22.
  2. No fixed version is listed for Cisco RV Series Routers itself; fixed versions for the other affected products are listed on this page.
  3. Until it is patched, review who holds accounts that can reach it.
  4. Check exposed instances for signs of compromise, not only for the version.

Description from NVD

A vulnerability in the web-based management interface of certain Cisco Small Business RV Series Routers could allow an authenticated, remote attacker to execute arbitrary commands with root privileges. The attacker must have either a valid credential or an active session token. The vulnerability is due to lack of input validation of the HTTP payload. An attacker could exploit this vulnerability by sending a malicious HTTP request to the web-based management interface of the targeted device. A successful exploit could allow the attacker to execute commands with root privileges.

What this means for your architecture.

A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.

Components it touches

  • Network edge devices: VPNs, firewalls, routers and gateways. They sit between the internet and internal networks, so a flaw in one is often the first step into everything behind it.
  • Operating systems on servers, workstations or devices. Everything on the host inherits the flaw.
  • APIs, queues and caches that accept serialized objects. The flaw sits between a message producer and the service that deserializes it.

Trust boundaries in play

  • Authenticated network access. An account is needed, so exposure follows who can sign in: customers, partners or staff.
  • Between a message producer and the service that deserializes it. An attacker who crosses it can turn crafted data into code execution inside the receiving service.

Questions to answer about your own systems

  • Where does Cisco RV Series Routers run in your systems, and at which version?
  • Which of those instances can be reached from the internet or partner networks?
  • What can it reach once compromised: which data stores, secrets and services?

Sources

  • CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
  • Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
  • Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
  • Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.