# [CRIT] CISA KEV: CVE-2017-9805 — Apache Struts Deserialization of Untrusted Data Vulnerability

**Source:** CISA KEV
**Published:** 2021-11-03
**Article:** https://www.cisa.gov/known-exploited-vulnerabilities-catalog

## Threat Profile

CISA KEV entry. The U.S. federal "Known Exploited Vulnerabilities" catalog only adds CVEs that have been **observed exploited in the wild**. Federal civilian agencies are required to remediate by the published due date; the same prioritisation logic applies to any sensible enterprise SOC.

Vendor / Product: **Apache Struts Deserialization of Untrusted Data**

## Indicators of Compromise

- CVE-2017-9805 — match against your vulnerability scanner

## MITRE ATT&CK

- **T1190 — Exploit Public-Facing Application** (KEV implies active exploitation against exposed assets)

## Recommended hunts

Standard asset-exposure hunt — the canonical Splunk SPL and Defender KQL
live once in [`../_TEMPLATES.md#asset-exposure`](../_TEMPLATES.md#asset-exposure).
Substitute this CVE wherever the template references `<CVE>`:

- **CVE:** `CVE-2017-9805`

## Why this matters

Anything in CISA KEV is *currently* being exploited. Even if your scanners say "not vulnerable" because of patches, it's worth one quick check across your fleet — patch lag is the silent killer. Federal due-date dates also frequently match the timing your organisation will be asked about by auditors / regulators.

## Source body

Apache Struts REST Plugin uses an XStreamHandler with an instance of XStream for deserialization without any type filtering, which can lead to remote code execution when deserializing XML payloads. Vendor: Apache, Product: Struts. Federal patch due: 2022-05-03. CVE-2017-9805