VulnerabilityPublished 30 Apr 2024Updated 2 Aug 2024

CVE-2024-33831: yapi · A Stored Cross-site Scripting (XSS)

Affects yapiSource CVE Database V5

Not known to be exploited · CVSS 7.4 High.

Data as of 26 Oct 2026, 08:30 UTC

CVSS 3.1 base score

7.4High

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 42% 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:C/C:H/I:N/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Changed
Confidentiality: High
Integrity: None
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: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within 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 30 Apr 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 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
GitHubymfe/yapi`pkg:github/ymfe/yapi`Other threats	Affected =1.10.2	Fixed in–

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AI-suggested

To mitigate CVE-2024-33831 effectively, organizations should first upgrade yapi to a version where this vulnerability is patched once available. In the interim, implement strict input validation on the 'body' field within the Advanced Expectation - Response module to reject or sanitize any HTML or script content. Employ robust output encoding or context-aware escaping to neutralize any injected scripts before rendering content in users' browsers. Restrict access to the vulnerable module to trusted users only, minimizing exposure to untrusted or anonymous users. Use Content Security Policy (CSP) headers to limit the execution of unauthorized scripts and reduce the impact of potential XSS payloads. Monitor logs and user activity for suspicious input patterns or unusual behavior indicative of exploitation attempts. Educate users about the risks of interacting with untrusted links or content within the yapi environment. Finally, conduct regular security assessments and code reviews focusing on input handling and sanitization to prevent similar vulnerabilities.

Description

A stored cross-site scripting (XSS) vulnerability in the Advanced Expectation - Response module of yapi v1.10.2 allows attackers to execute arbitrary web scripts or HTML via a crafted payload injected into the body field.

Impact

The primary impact of CVE-2024-33831 is the compromise of user confidentiality through the execution of arbitrary scripts in victims' browsers. Attackers can steal session tokens, cookies, or other sensitive information, potentially leading to account takeover or unauthorized access to sensitive API data managed by yapi. The vulnerability does not directly affect data integrity or availability but can indirectly facilitate further attacks such as phishing or malware distribution. Organizations relying on yapi for API management or documentation may suffer reputational damage and loss of user trust if exploited. Since the vulnerability requires user interaction, phishing or social engineering could be used to lure victims into triggering the malicious payload. The scope change indicates that exploitation could affect multiple components or users beyond the initially targeted module, increasing the potential attack surface. Given yapi's usage in software development and API lifecycle management, exploitation could disrupt development workflows or leak proprietary information. The absence of known exploits in the wild currently limits immediate widespread impact but does not reduce the urgency of remediation.

CWE-80Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS) (opens in a new tab)
Variant weaknessLikelihood of exploit: HighOWASP Top 10 A05:2025: Injection (opens in a new tab)
The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special characters such as "<", ">", and "&" that could be interpreted as web-scripting elements when they are sent to a downstream component that processes web pages.
Implementation
Carefully check each input parameter against a rigorous positive specification (allowlist) defining the specific characters and format allowed. All input should be neutralized, not just parameters that the user is supposed to specify, but all data in the request, including hidden fields, cookies, headers, the URL…
Implementation · Output Encoding
Use and specify an output encoding that can be handled by the downstream component that is reading the output. Common encodings include ISO-8859-1, UTF-7, and UTF-8.
Implementation
With Struts, write all data from form beans with the bean's filter attribute set to true.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
Deserialization (opens in a new tab)
Cross Site Scripting Prevention (opens in a new tab)
DOM based XSS Prevention (opens in a new tab)
Injection Prevention (opens in a new tab)
OWASP ASVS 4.0.3
V1.5.1 (opens in a new tab)
V5.3.3 (opens in a new tab)
Attack patterns
XSS Targeting Non-Script Elements (opens in a new tab)
PHP Remote File Inclusion (opens in a new tab)
XSS Through HTTP Query Strings (opens in a new tab)
XSS Through HTTP Headers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/YMFE/yapi/issues/2745 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Feb 2026, 04:36 UTC

WeaknessesCWE-80

Technical details

References

Community reviews

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