VulnerabilityPublished 29 May 2025

CVE-2025-5323: fossasia open-event-server · Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking in

Affects fossasia open-event-serverSource CVE Database V5

Not known to be exploited · CVSS 6.3 Medium.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 4.0 base score

6.3Medium

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, 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: 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: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within 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: None: There is no impact to availability within 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.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 29 May 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

Affected software

Product	Affected	Fixed in
PyPIopen-event-server`pkg:pypi/open-event-server`Other threats	Affected =1.19.1	Fixed in–

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AI-suggested

2) Restrict network access to the open-event-server instance by implementing strict firewall rules and network segmentation to limit exposure to untrusted networks. 3) Monitor and log all email change requests and related API calls for anomalies or unusual patterns that could indicate exploitation attempts. 4) Employ multi-factor authentication (MFA) for user account changes to add an additional layer of verification beyond email confirmation. 5) Consider upgrading to a later version of the software if available or applying custom patches to address the integrity checking deficiency. 6) Engage with the fossasia community or maintainers to encourage timely patch development and share threat intelligence related to this vulnerability.

Description

A vulnerability, which was classified as problematic, has been found in fossasia open-event-server 1.19.1. This issue affects the function send_email_change_user_email of the file /fossasia/open-event-server/blob/development/app/api/helpers/mail.py of the component Mail Verification Handler. The manipulation leads to reliance on obfuscation or encryption of security-relevant inputs without integrity checking. The attack may be initiated remotely. The complexity of an attack is rather high. The exploitation is known 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 using fossasia open-event-server 1.19.1, this vulnerability could undermine the integrity of email change verification processes. This could allow attackers to manipulate email change requests, potentially leading to unauthorized account modifications or hijacking. Such unauthorized changes could disrupt user account management, erode trust in event management platforms, and expose organizations to further attacks or data inconsistencies. While the vulnerability does not directly compromise confidentiality or availability, the integrity breach could have cascading effects, such as enabling phishing or social engineering attacks by altering contact information. Given the open-source nature of the software and its use in event management, organizations involved in conferences, community events, or academic gatherings across Europe could face operational disruptions and reputational damage if exploited.

Summary

CVE-2025-5323 is a medium-severity vulnerability identified in version 1.19.1 of the fossasia open-event-server, specifically within the Mail Verification Handler component. The flaw resides in the function send_email_change_user_email located in the mail.py file. The vulnerability stems from the system's reliance on obfuscation or encryption of security-relevant inputs without implementing integrity checks. This means that while the inputs may be encrypted or obfuscated, there is no mechanism to verify that these inputs have not been tampered with during transmission or processing. An attacker could potentially manipulate these inputs remotely, although the attack complexity is considered high and exploitation is difficult. No authentication or user interaction is required for exploitation, and the attack vector is network-based. The CVSS 4.0 score of 6.3 reflects a medium severity, indicating a moderate impact primarily on the integrity of the system, with no direct impact on confidentiality or availability. This lack of vendor engagement increases the risk for organizations relying on this software, as mitigations must be implemented independently until an official fix is available.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 7 Jul 2025, 22:39 UTC

Technical details

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