Cyber Resilience

CVE-2025-27913

Passbolt Api ≤ 5.0.0

Published
10 March 2025
Modified
19 June 2025
Patch / advisory
CVSS Score v4 2.1
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0018 8th percentile
Risk Priority 15 floored blend · peak EPSS

Summary

CVE-2025-27913 is a low-severity Use of Less Trusted Source (CWE-348) vulnerability in Passbolt Passbolt Api. Its CVSS base score is 2.1 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique Path Interception (T1034); ranked at the 8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-4 (Information Flow Enforcement) and IA-3 (Device Identification and Authentication) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2025-27913 affects the Passbolt API in versions before 5. The vulnerability arises when the server is misconfigured through an incorrect installation process and disregard of Health Check results, enabling the API to send email messages that incorporate a domain name sourced from an attacker-controlled HTTP Host header. This constitutes a Host Header Injection issue, mapped to CWE-348, with a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N).

Remote attackers require no privileges or user interaction to exploit this vulnerability over the network with low complexity. By crafting HTTP requests with a manipulated Host header, they can influence the domain used in emails sent by the Passbolt server, achieving high integrity impact through potential email spoofing.

The official advisory from Passbolt, available at https://www.passbolt.com/incidents/host-header-injection, provides details on mitigation steps for this issue.

EU & UK References

Vulnerability Data

Passbolt API before 5, if the server is misconfigured (with an incorrect installation process and disregarding of Health Check results), can send email messages with a domain name taken from an attacker-controlled HTTP Host header.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1034 Path Interception Persistence
**This technique has been deprecated.
T1557.001 Name Resolution Poisoning and SMB Relay Credential Access
By responding to LLMNR/NBT-NS/mDNS network traffic, adversaries may spoof an authoritative source for name resolution to force communication with an adversary controlled system.
T1557.002 ARP Cache Poisoning Credential Access
Adversaries may poison Address Resolution Protocol (ARP) caches to position themselves between the communication of two or more networked devices.
T1557.003 DHCP Spoofing Credential Access
Adversaries may redirect network traffic to adversary-owned systems by spoofing Dynamic Host Configuration Protocol (DHCP) traffic and acting as a malicious DHCP server on the victim network.
T1557 Adversary-in-the-Middle Credential Access
Adversaries may attempt to position themselves between two or more networked devices using an adversary-in-the-middle (AiTM) technique to support follow-on behaviors such as [Network Sniffing](https://attack.
T1584.002 DNS Server Resource Development
Adversaries may compromise third-party DNS servers that can be used during targeting.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-33670Same product: Passbolt Passbolt Api
CVE-2025-24856Shared CWE-348
CVE-2025-58422Shared CWE-348
CVE-2026-22201Shared CWE-348
CVE-2026-63770Shared CWE-348
CVE-2026-24910Shared CWE-348
CVE-2026-12249Shared CWE-348
CVE-2026-33690Shared CWE-348
CVE-2026-35391Shared CWE-348
CVE-2026-59897Shared CWE-348

Affected Assets

passbolt
passbolt api
≤ 5.0.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 7 hardening rules · 4 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

Provenance tracking supplies the information needed to distinguish and prefer more-trusted sources, reducing the chance that a weaker source is chosen.

Information flow enforcement can require that data or decisions are taken only from explicitly approved, higher-trust sources rather than less-verified ones.

Device identification and authentication forces verification of the source before any data it supplies is used, eliminating reliance on unauthenticated inputs.

Boundary protection monitors and filters traffic at external interfaces, structurally limiting the ability to accept data from less-trusted external sources.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

ID.RA-09 mostly match
prevents

Explicit authenticity/integrity checks before use directly reduce selection of a less-trusted source.

DE.AE-03 partial match
prevents

Correlating multiple sources can surface discrepancies that discourage reliance on the less-trusted one.

PR.DS-02 partial match
prevents

Protecting data-in-transit integrity helps ensure the more-trusted source is the one whose data is accepted.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Secure architecture principles include trusted input channels and source verification mechanisms.

finds

Security testing can detect and prevent acceptance of data from less-trusted sources during development.

degrades

Network security controls can enforce trusted data paths and source validation, reducing reliance on unverified inputs.

degrades

Secure network services include source validation and integrity checks that help prevent acceptance of data from less-trusted origins.

prevents

Application security requirements can mandate trusted data sources and input validation, directly addressing the weakness.

prevents

Secure coding practices can enforce checks that prefer or validate the more trusted data source.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (1 rule)
  • V-248575 OL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-348
Oracle Linux 9 (1 rule)
  • V-271525 OL 9 must have GPG signature verification enabled for all software repositories. prevents CWE-348
RHEL 7 (1 rule)
  • V-204447 The Red Hat Enterprise Linux operating system must prevent the installation of software, patches, service packs, device drivers, or operating system components from a repository without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-348

References