VulnerabilityPublished 23 Jun 2024Updated 13 Nov 2024

CVE-2024-39334: MENDELSON AS4 · Deserialization of Untrusted Data

Source CVE Database V5

Not known to be exploited · CVSS 6.5 Medium.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 3.1 base score

6.5Medium

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 28% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
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: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 23 Jun 2024
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

Apply vendor patches or updates for MENDELSON AS4 as soon as they become available, specifically upgrading to version 2024 B376 or later.
Until patches are deployed, restrict or closely monitor incoming AS4 transactions from untrusted or unknown trading partners to reduce exposure to malicious XML payloads.
Implement strict validation and sanitization of XML data on the client side, if possible, to detect and block malformed or suspicious payloads before processing.
Educate users about the risks of opening transaction details from unverified sources to reduce the likelihood of social engineering exploitation.
Employ endpoint protection solutions capable of detecting anomalous file writes or suspicious client application behavior.
Consider network segmentation or application whitelisting to limit the impact of potential client compromise.
Monitor logs and client behavior for signs of exploitation attempts or unusual file modifications related to MENDELSON AS4 client activity.
Collaborate with trading partners to ensure secure and verified message exchanges and to share threat intelligence regarding suspicious payloads.

Description

MENDELSON AS4 before 2024 B376 has a client-side vulnerability when a trading partner provides prepared XML data. When a victim opens the details of this transaction in the client, files can be written to the computer on which the client process is running. (The server process is not affected.)

Impact

The primary impact of CVE-2024-39334 is on the integrity of client systems running vulnerable MENDELSON AS4 software. Successful exploitation allows an attacker to write arbitrary files on the client machine, which could lead to code execution, persistence, or manipulation of client-side data. Although confidentiality and availability are not directly affected, the ability to modify files can facilitate further attacks such as malware deployment or tampering with business-critical data. Since the vulnerability requires user interaction to open malicious transaction details, social engineering is a key risk factor. Organizations relying on MENDELSON AS4 for secure B2B message exchange may face risks of client compromise, especially if trading partners are untrusted or if attackers can intercept or inject malicious XML payloads. The vulnerability does not affect the server, limiting the scope to client endpoints, but given the critical role of AS4 clients in business workflows, the operational impact could be significant. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as the vulnerability is publicly disclosed.

CWE-502Deserialization of Untrusted Data (opens in a new tab)
Base weaknessLikelihood of exploit: MediumCWE Top 25 (2025): #15OWASP Top 10 A08:2025: Software or Data Integrity Failures (opens in a new tab)
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
Architecture and Design · Implementation
If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
Implementation
When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
Implementation
Explicitly define a final object() to prevent deserialization.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
Deserialization (opens in a new tab)
XML Security (opens in a new tab)
XML External Entity Prevention (opens in a new tab)
Software Supply Chain Security (opens in a new tab)
OWASP ASVS 4.0.3
V1.5.2 (opens in a new tab)
V5.5.3 (opens in a new tab)
V5.5.1 (opens in a new tab)
Attack patterns
Object Injection (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

mendelson-e-c.com/node/27845 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 28 Feb 2026, 04:22 UTC

WeaknessesCWE-502

Technical details

References

Community reviews

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