CVE-2024-1874VulnerabilityPublished 14 May 2024Updated 4 Nov 2025

CVE-2024-1874: PHP · Improper Encoding or Escaping of Output

Affects PHPSource CVE Database V5

Not known to be exploited · 32% EPSS · CVSS 9.4 Critical · fixed in 8.3.5 : patch PHP as a priority.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

9.4Critical

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

EPSS: 32.5% chance of exploitation in 30 days – higher than 98% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 8.3.5, 8.2.18, 8.1.28

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

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

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: 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: 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: 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 impacted component 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 impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 14 May 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 2026-10-25.

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

Upgrade debian/php to 8.3.5, 8.2.18 or 8.1.28.

Affected software

Product	Affected	Fixed in
Debiandebian/php`pkg:deb/debian/php`Other threats	Affected <8.1.28 <8.2.18 <8.3.5	Fixed in 8.1.28 8.2.18 8.3.5

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

1. Immediately upgrade PHP installations to versions 8.1.28, 8.2.18, or 8.3.5 or later where the vulnerability is patched. 2. If immediate patching is not possible, restrict usage of proc_open() with array syntax on Windows systems, especially where user input controls command arguments. 3. Implement strict input validation and sanitization on all user-supplied data that might be passed to system commands, employing whitelisting approaches where feasible. 4. Employ application-layer firewalls or web application firewalls (WAFs) to detect and block suspicious command injection patterns targeting proc_open() usage. 5. Monitor logs for unusual command execution attempts or anomalies in PHP process spawning. 6. Limit PHP execution privileges and isolate PHP applications in containers or sandboxes to reduce impact scope. 7. Conduct security audits and code reviews focusing on usage of proc_open() and other system command invocations. 8. Educate developers about secure coding practices related to command execution and escaping on Windows platforms. 9. Maintain up-to-date backups and incident response plans to quickly recover from potential compromises.

Description

In PHP versions 8.1.* before 8.1.28, 8.2.* before 8.2.18, 8.3.* before 8.3.5, when using proc_open() command with array syntax, due to insufficient escaping, if the arguments of the executed command are controlled by a malicious user, the user can supply arguments that would execute arbitrary commands in Windows shell.

Impact

For European organizations, the impact of CVE-2024-1874 can be severe, particularly for those running PHP-based web applications on Windows servers. Successful exploitation allows attackers to execute arbitrary commands remotely, potentially leading to full system compromise, data breaches, and disruption of services. This can affect confidentiality by exposing sensitive data, integrity by allowing unauthorized changes, and availability by enabling denial-of-service conditions. Organizations in sectors such as finance, healthcare, government, and critical infrastructure are especially at risk due to the sensitive nature of their data and regulatory requirements like GDPR. The vulnerability's ease of exploitation and lack of authentication requirements increase the likelihood of targeted attacks or automated scanning and exploitation attempts. Additionally, compromised systems could be used as footholds for broader attacks within European networks, amplifying the threat. The absence of known exploits in the wild currently provides a window for proactive mitigation, but the critical severity demands urgent attention.

CWE-116Improper Encoding or Escaping of Output (opens in a new tab)
Class weaknessLikelihood of exploit: HighOWASP Top 10 A05:2025: Injection (opens in a new tab)
The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Architecture and Design · Parameterization
If available, use structured mechanisms that automatically enforce the separation between data and code. These mechanisms may be able to provide the relevant quoting, encoding, and validation automatically, instead of relying on the developer to provide this capability at every point where output is generated.
Architecture and Design · Implementation
Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages.
OWASP Cheat Sheets
Content Security Policy (opens in a new tab)
Injection Prevention (opens in a new tab)
SQL Injection Prevention (opens in a new tab)
Injection Prevention in Java (opens in a new tab)
Query Parameterization (opens in a new tab)
OWASP ASVS 4.0.3
V14.4.6 (opens in a new tab)
V14.4.4 (opens in a new tab)
V14.4.2 (opens in a new tab)
Attack patterns
Cross Zone Scripting (opens in a new tab)
User-Controlled Filename (opens in a new tab)
Web Server Logs Tampering (opens in a new tab)
AJAX Footprinting (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 4 Nov 2025, 18:12 UTC

WeaknessesCWE-116

Technical details

References

Community reviews

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