ATT&CK technique · T1505.003
Server Software Component: Web Shell
Persistence· seen in 26 CISA KEV exploits
Full description, procedures and detections on attack.mitre.org
Who uses it
ATT&CK groups and malware with this technique. Highlighted: in SecurityTabs news this month.
Weaknesses that lead here
Classes of exploited vulnerability that CTID maps to this technique.
- CWE-2873 KEV CVEsImproper AuthenticationThe system doesn't properly prove who a user is, so attackers get in as someone else.
- CWE-2883 KEV CVEsAuthentication Bypass Using an Alternate Path or ChannelA second route (a debug port, an API) reaches the protected function without the login check.
- CWE-2903 KEV CVEsAuthentication Bypass by SpoofingThe system trusts something an attacker can fake, such as a source address or header.
- CWE-5023 KEV CVEsDeserialization of Untrusted DataUntrusted bytes are turned back into live objects, which can trigger code during reconstruction.
- CWE-4342 KEV CVEsUnrestricted Upload of File with Dangerous TypeUploads aren't restricted, so an attacker uploads a script (a web shell) and then requests it.
- CWE-13211 KEV CVEImproperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')Input changes the base prototype of JavaScript objects, altering behaviour across the whole application.
- CWE-221 KEV CVEImproper Limitation of a Pathname to a Restricted Directory ('Path Traversal')Sequences like ../ in a file path escape the intended folder, exposing or overwriting other files.
- CWE-231 KEV CVERelative Path TraversalRelative ../ segments in input climb out of the allowed directory.
Controls that mitigate it (8)
NIST SP 800-53 rev5, grouped by family (CTID mapping).
AC · Access Control
CM · Configuration Management
RA · Risk Assessment
SI · System and Information Integrity
Weaknesses from each CVE's CVE Record (CWE, © MITRE). Techniques: MITRE ATT&CK®. Technique ↔ control and CVE ↔ technique links: Center for Threat-Informed Defense Mappings Explorer (NIST SP 800-53 rev5; CISA KEV). Plain-language explainers are SecurityTabs editorial.