VulnerabilityPublished 6 Jun 2025Updated 9 Jun 2025

CVE-2025-5715: Signal App · Missing Critical Step in Authentication

Affects Signal AppSource CVE Database V5

Public exploit available · CVSS 1.0 Low.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 4.0 base score

1.0Low

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 21% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:P/AC:H/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P

Base metrics

Attack Vector: Physical
Attack Complexity: High
Attack Requirements: None
Privileges Required: Low
User Interaction: None
Vulnerable system confidentiality: Low
Vulnerable system integrity: Low
Vulnerable system availability: Low
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Threat metrics

Exploit Maturity: POC

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Physical: The attack requires the attacker to physically touch or manipulate the vulnerable system. Physical interaction may be brief (e.g., evil maid attack) or persistent.
Attack Complexity: High: The successful attack depends on the evasion or circumvention of security-enhancing techniques in place that would otherwise hinder the attack. These include: Evasion of exploit mitigation techniques, for example, circumvention of address space randomization (ASLR) or data execution prevention (DEP) must be performed for the attack to be successful; Obtaining target-specific secrets. The attacker must gather some target-specific secret before the attack can be successful. A secret is any piece of information that cannot be obtained through any amount of reconnaissance. To obtain the secret the attacker must perform additional attacks or break otherwise secure measures (e.g. knowledge of a secret key may be needed to break a crypto channel). This operation must be performed for each attacked target.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: Low: The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Vulnerable System.
Vulnerable system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Vulnerable System.
Vulnerable system availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the Vulnerable System are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.
Exploit Maturity: POC: Based on threat intelligence sources each of the following must apply: · Proof-of-concept is publicly available · No knowledge of reported attempts to exploit this vulnerability · No knowledge of publicly available solutions used to simplify attempts to exploit the vulnerability

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 6 Jun 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
CVSS exploit maturity: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Signal App	Affected =7.41.4	Fixed in–

AI-suggested

Given the absence of an official patch from the vendor, European organizations and users should adopt specific mitigation strategies beyond generic advice: 1) Enforce strict physical security controls to prevent unauthorized access to devices running Signal, including secure storage and use of device locks. 2) Encourage users to update Signal promptly once a patched version is released; meanwhile, consider temporarily limiting the use of biometric authentication within the app if possible, or disable biometric unlock features at the OS level. 3) Implement device management policies that restrict installation of vulnerable app versions and monitor for unauthorized device access attempts. 4) Educate users about the risks of physical device compromise and promote the use of strong passcodes or PINs as an additional authentication layer. 5) Consider using additional endpoint security solutions that can detect or prevent unauthorized access attempts on mobile devices. 6) Monitor threat intelligence feeds for any emerging exploit activity related to this CVE to respond swiftly if exploitation in the wild is detected.

Description

A vulnerability was found in Signal App 7.41.4 on Android. It has been declared as problematic. This vulnerability affects unknown code of the component Biometric Authentication Handler. The manipulation leads to missing critical step in authentication. It is possible to launch the attack on the physical device. The complexity of an attack is rather high. The exploitation appears to be difficult. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

Impact

For European organizations, the impact of CVE-2025-5715 is relatively limited due to the requirement of physical access and the high complexity of exploitation. However, Signal is widely used for secure communications, including by journalists, activists, and professionals handling sensitive information. A successful bypass of biometric authentication could lead to unauthorized access to private communications, potentially exposing confidential organizational data or personal information. This could have reputational consequences and may violate data protection regulations such as GDPR if personal data is compromised. The threat is more pronounced in environments where devices are at risk of theft or unauthorized physical access, such as in public or insecure workspaces. Since Signal is often used for end-to-end encrypted messaging, any compromise of device-level authentication could undermine trust in secure communications within European entities relying on the app for privacy.

Summary

CVE-2025-5715 is a vulnerability identified in the Signal App version 7.41.4 on Android devices, specifically within the Biometric Authentication Handler component. The flaw results from a missing critical step in the authentication process, which could potentially allow an attacker with physical access to the device to bypass biometric authentication mechanisms. The vulnerability is characterized by a high attack complexity and difficult exploitation conditions, meaning that an attacker would require significant skill and access to the physical device to successfully exploit the flaw. The vulnerability does not require user interaction, but it does require local privileges (low privileges) and physical access to the device. The CVSS v4.0 score is 1.0, indicating a low severity level, primarily because of the high complexity and limited scope of impact. The vendor, Signal, was contacted early about this issue but has not responded or issued a patch, and no known exploits are currently observed in the wild. The vulnerability could potentially allow an attacker to bypass biometric authentication, undermining the confidentiality and integrity of the user's communications and data within the Signal app. However, the lack of remote exploitability and the requirement for physical device access significantly limit the threat's scope and impact.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 7 Jul 2025, 19:12 UTC

Technical details

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