VulnerabilityPublished 6 Nov 2025Updated 8 Dec 2025

CVE-2025-27917: AnyDesk · NULL Pointer Dereference

Source CVE Database V5

Not known to be exploited · CVSS 7.5 High · fixed in 9.0.5 : patch Windows soon.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

7.5High

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

EPSS: 0.5% chance of exploitation in 30 days – higher than 42% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Affects: Windows before 9.0.5
Patch: Available – fixed in 9.0.5, 9.0.1, 8.0.0 +2

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

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

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 6 Nov 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
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), 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

AI-suggested

Organizations should immediately verify the AnyDesk versions deployed across all platforms and upgrade to the fixed versions: 9.0.5 or later for Windows, 9.0.1 or later for macOS, 7.0.0 or later for Linux, 7.1.2 or later for iOS, and 8.0.0 or later for Android. If immediate patching is not feasible, consider restricting AnyDesk network access via firewall rules to trusted IP addresses and monitoring network traffic for unusual connection attempts. Implement network segmentation to isolate critical systems from endpoints running vulnerable AnyDesk versions. Enable logging and alerting on AnyDesk service crashes or restarts to detect potential exploitation attempts. Educate IT staff about this vulnerability and incorporate it into incident response plans. Additionally, consider alternative remote access solutions temporarily if patching is delayed. Employ endpoint protection solutions capable of detecting anomalous application behavior related to memory errors or crashes.

Description

An issue was discovered in AnyDesk for Windows before 9.0.5, AnyDesk for macOS before 9.0.1, AnyDesk for Linux before 7.0.0, AnyDesk for iOS before 7.1.2, and AnyDesk for Android before 8.0.0. Remote Denial of Service can occur because of incorrect deserialization that results in failed memory allocation and a NULL pointer dereference.

Impact

For European organizations, the primary impact of CVE-2025-27917 is on the availability of remote desktop services provided by AnyDesk. Disruption of remote access can hinder business continuity, especially for companies with distributed workforces or those relying on remote support and administration. Critical sectors such as finance, healthcare, and government services that utilize AnyDesk for secure remote operations could experience operational delays or outages. The vulnerability does not compromise confidentiality or integrity directly but can cause denial of service, potentially leading to loss of productivity and increased support costs. Given the cross-platform nature of the vulnerability, organizations using AnyDesk on various devices are at risk. The lack of required authentication or user interaction lowers the barrier for attackers to exploit this flaw remotely, increasing the threat level. Although no active exploitation is reported, the high severity score and ease of exploitation necessitate urgent remediation to prevent potential attacks that could disrupt services across Europe.

CWE-476NULL Pointer Dereference (opens in a new tab)
Base weaknessLikelihood of exploit: MediumCWE Top 25 (2025): #13OWASP Top 10 A10:2025: Mishandling of Exceptional Conditions (opens in a new tab)
The product dereferences a pointer that it expects to be valid but is NULL.
Implementation
For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
Requirements
Select a programming language that is not susceptible to these issues.
Implementation
Check the results of all functions that return a value and verify that the value is non-null before acting upon it.
OWASP Cheat Sheets
Logging (opens in a new tab)
Error Handling (opens in a new tab)
OWASP ASVS 4.0.3
V11.1.7 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 8 Dec 2025, 17:50 UTC

WeaknessesCWE-476

Technical details

References

Community reviews

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