Tên: Server-Side Request Forgery

The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.

Thông tin chung

Các cách xuất hiện

Architecture and Design
Implementation

Nền tảng áp dụng

Ngôn ngữ

Lớp: Not Language-Specific (Undetermined)

Công nghệ

Lớp: Web Based (Undetermined)
Tên: AI/ML (Often)
Tên: Web Server (Undetermined)

Hậu quả phổ biến

Phạm vi	Tác động	Khả năng xảy ra
Confidentiality	Read Application Data
Integrity	Execute Unauthorized Code or Commands
Access Control	Bypass Protection Mechanism Ghi chú: By providing URLs to unexpected hosts or ports, attackers can make it appear that the server is sending the request, possibly bypassing access controls such as firewalls that prevent the attackers from accessing the URLs directly. The server can be used as a proxy to conduct port scanning of hosts in internal networks, use other URLs such as that can access documents on the system (using file://), or use other protocols such as gopher:// or tftp://, which may provide greater control over the contents of requests.

Ví dụ đã quan sát

Tài liệu tham khảo	Mô tả
CVE-2026-33626	SSRF in LLM toolkit accesses arbitrary URLs for images, as exploited in the wild in April 2026 to conduct port scanning [REF-1519]
CVE-2024-3095	SSRF in LLM application development framework because the URL retriever allows connections to local addresses using a crafted Location header
CVE-2023-32786	Chain: LLM integration framework has prompt injection (CWE-1427) that allows an attacker to force the service to retrieve data from an arbitrary URL, essentially providing SSRF (CWE-918) and potentially injecting content into downstream tasks.
CVE-2021-26855	Server Side Request Forgery (SSRF) in mail server, as exploited in the wild per CISA KEV.
CVE-2021-21973	Server Side Request Forgery in cloud platform, as exploited in the wild per CISA KEV.
CVE-2016-4029	Chain: incorrect validation of intended decimal-based IP address format (CWE-1286) enables parsing of octal or hexadecimal formats (CWE-1389), allowing bypass of an SSRF protection mechanism (CWE-918).
CVE-2002-1484	Web server allows attackers to request a URL from another server, including other ports, which allows proxied scanning.
CVE-2004-2061	CGI script accepts and retrieves incoming URLs.
CVE-2010-1637	Web-based mail program allows internal network scanning using a modified POP3 port number.
CVE-2009-0037	URL-downloading library automatically follows redirects to file:// and scp:// URLs

Các biện pháp giảm thiểu tiềm năng

Phases : Implementation // Operation
If there is a known list of applications, IP, hostname, and/or domains to which the product is allowed to communicate, then use allowlists to ensure that outgoing requests are restricted to these known entities. The allowlists could be in the application code or possibly enforced by firewalls or network segmentation [REF-1511].
Phases : Implementation // Operation
If the product is expected to be able to connect to arbitrary IP addresses or domains, consider using a denylist that includes private network addresses, internal domain names, etc. The denylist could be in the application code or possibly enforced by firewalls or network segmentation [REF-1511].
Phases : Implementation

Phương pháp phát hiện

Automated Static Analysis

Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)
Hiệu quả : High

Ghi chú ánh xạ lỗ hổng

Lý do : This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.
Bình luận : Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.

Mẫu tấn công liên quan

ID CAPEC	Tên mẫu tấn công
CAPEC-664	Server Side Request Forgery

Ghi chú

CWE-918 (SSRF) and CWE-611 (XXE) are closely related, because they both involve web-related technologies and can launch outbound requests to unexpected destinations. However, XXE can be performed client-side, or in other contexts in which the software is not acting directly as a server, so the "Server" portion of the SSRF acronym does not necessarily apply.

Tài liệu tham khảo

REF-913

SSRF vs. Business-critical applications: XXE tunneling in SAP
Alexander Polyakov, Dmitry Chastukhin.
https://media.blackhat.com/bh-us-12/Briefings/Polyakov/BH_US_12_Polyakov_SSRF_Business_Slides.pdf

REF-914

SSRF vs. Business-critical Applications. Part 1: XXE Tunnelling in SAP NetWeaver
Alexander Polyakov, Dmitry Chastukhin, Alexey Tyurin.
http://erpscan.com/wp-content/uploads/2012/08/SSRF-vs-Businness-critical-applications-whitepaper.pdf

REF-1519

CVE-2026-33626: How attackers exploited LMDeploy LLM Inference Engines in 12 hours
Sysdig Threat Research Team.
https://www.sysdig.com/blog/cve-2026-33626-how-attackers-exploited-lmdeploy-llm-inference-engines-in-12-hours

Gửi

Tên	Tổ chức	Ngày	Ngày phát hành	Version
CWE Content Team	MITRE	2013-02-17 +00:00	2013-02-21 +00:00	2.4

Sửa đổi

Tên	Tổ chức	Ngày	Bình luận
CWE Content Team	MITRE	2015-12-07 +00:00	updated Relationships
CWE Content Team	MITRE	2017-01-19 +00:00	updated Relationships
CWE Content Team	MITRE	2017-11-08 +00:00	updated Applicable_Platforms, References
CWE Content Team	MITRE	2018-03-27 +00:00	updated References
CWE Content Team	MITRE	2019-06-20 +00:00	updated Relationships
CWE Content Team	MITRE	2020-02-24 +00:00	updated Applicable_Platforms, Relationships
CWE Content Team	MITRE	2021-07-20 +00:00	updated References, Related_Attack_Patterns, Relationships
CWE Content Team	MITRE	2021-10-28 +00:00	updated Relationships
CWE Content Team	MITRE	2022-06-28 +00:00	updated Observed_Examples, Relationships
CWE Content Team	MITRE	2022-10-13 +00:00	updated Observed_Examples
CWE Content Team	MITRE	2023-04-27 +00:00	updated Detection_Factors, References, Relationships
CWE Content Team	MITRE	2023-06-29 +00:00	updated Mapping_Notes, Relationships
CWE Content Team	MITRE	2024-11-19 +00:00	updated Alternate_Terms, Common_Consequences, Description, Diagram, Observed_Examples, Relationships
CWE Content Team	MITRE	2025-09-09 +00:00	updated Applicable_Platforms, Observed_Examples, References
CWE Content Team	MITRE	2025-12-11 +00:00	updated Applicable_Platforms, Demonstrative_Examples, References, Relationships, Weakness_Ordinalities
CWE Content Team	MITRE	2026-04-30 +00:00	updated Applicable_Platforms, Observed_Examples, References, Relationships
CWE Content Team	MITRE	2026-10-28 +00:00	updated Name, Potential_Mitigations

Chi tiết CWE-918

CWE-918