Backdrop CMS Host Header Injection vulnerability

Description

Host Header Injection vulnerability in Backdrop CMS 1.32.1 allows attackers to manipulate the Host header in password reset requests, leading to redirects to malicious domains and potential session hijacking via cookie injection.

Basic information

Type
reviewed
Severity
medium
Advisory on GitHub
Open advisory ↗
Repository advisory
Source code
Browse source ↗
Published (advisory)
2025-11-18 18:32:55 UTC
Updated
2025-11-19 18:59:50 UTC
GitHub reviewed
2025-11-18 21:56:57 UTC
NVD published
2025-11-18

EPSS Score

Score Percentile
0.04% 10.90%

CVSS Scores

Base score Version Severity Vector
6.9 4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N/E:P Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:N)
No additional preconditions are required beyond normal reachability.
Privileges required (PR:N)
No privileges are required.
User interaction (UI:A)
User interaction is required in an active way.
Vulnerable system confidentiality impact (VC:N)
No confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:H)
High integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:N)
No availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:N)
No confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:H)
High integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.
Exploit maturity (threat) (E:P)
Proof-of-concept: public PoC exists; no reported exploitation and no known simplification tools.

Identifiers

CWEs

CWE id Name
CWE-601 URL Redirection to Untrusted Site ('Open Redirect')
CWE-644 Improper Neutralization of HTTP Headers for Scripting Syntax

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
composer backdrop/backdrop <= 1.32.0

References

cvelogic Threat Intelligence