The ngx_http_parse_chunked function in http/ngx_http_parse.c in nginx 1.3.9 through 1.4.0 allows remote attackers to cause a denial of servi
The ngx_http_parse_chunked function in http/ngx_http_parse.c in nginx 1.3.9 through 1.4.0 allows remote attackers to cause a denial of service (crash) and execute arbitrary code via a chunked Transfer-Encoding request with a large chunk size, which triggers an integer signedness error and a stack-based buffer overflow.
Noroxi analysis
No Noroxi analysis for this record yet
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We use this product, ask for help- Published
- Jul 19, 2013
- Updated
- Jun 16, 2026
- EPSS
- 87.5% · 100th percentile
- CWE
- CWE-787
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Report tools
Action score
56
Plan
Add it to your regular patch cycle.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 26 / 30 · 87.5%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| f5 | nginx | cpe:2.3:a:f5:nginx |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
Using nginx? Add it to your stack and be the first to know about CVEs like this one. (Nginx)
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- f5 nginx1.3.9 and later · up to 1.4.0 inclusive
Same product
f5: all recordsOther highest-scoring records for the same primary product.
- CVE-2016-0742The resolver in nginx before 1.8.1 and 1.9.x before 1.9.10 allows remote attackers to cause a denial of service (invalid pointer dereference55Plan
- CVE-2009-2629Buffer underflow in src/http/ngx_http_parse.c in nginx 0.1.0 through 0.5.37, 0.6.x before 0.6.39, 0.7.x before 0.7.62, and 0.8.x before 0.8.53Plan
- CVE-2013-4547nginx 0.8.41 through 1.4.3 and 1.5.x before 1.5.7 allows remote attackers to bypass intended restrictions via an unescaped space character i50Plan
- CVE-2017-7529Nginx versions since 0.5.6 up to and including 1.13.2 are vulnerable to integer overflow vulnerability in nginx range filter module resultin49Plan
- CVE-2021-23017A security issue in nginx resolver was identified, which might allow an attacker who is able to forge UDP packets from the DNS server to cau46Plan
- CVE-2018-16843nginx before versions 1.15.6 and 1.14.1 has a vulnerability in the implementation of HTTP/2 that can allow for excessive memory consumption.44Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
Weaponized
A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.
Evidence
- Metasploit module ×1
- Exploit-DB entry ×4
- Proof-of-concept repository on GitHub ×8
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Exploit-DB entry | dos | 2013-05-17 |
| Exploit-DB entry | remote | 2013-05-28 |
| Exploit-DB entry | remote | 2013-07-11 |
| Exploit-DB entry | remote | 2014-03-15 |
| Metasploit module | exploit/linux/http/nginx_chunked_sizeNginx HTTP Server 1.3.9-1.4.0 Chunked Encoding Stack Buffer Overflowexploit | 2013-05-07 |
| Proof-of-concept repository on GitHub | stars:30 | 2013-05-21 |
| Proof-of-concept repository on GitHub | stars:55 | 2016-03-23 |
| Proof-of-concept repository on GitHub | stars:2 | 2019-08-03 |
| Proof-of-concept repository on GitHub | stars:19 | 2020-06-27 |
| Proof-of-concept repository on GitHub | stars:1 | 2021-07-08 |
| Proof-of-concept repository on GitHub | stars:0 | 2022-08-15 |
| Proof-of-concept repository on GitHub | stars:0 | 2024-07-23 |
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Metasploit-74 d
- First PoC-64 d
- Published
- TodaySep 30, 2026+4821 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- P · data can be read
- Integrity
- P · data or configuration can be modified
- Availability
- P · the service can be disrupted
- Attack complexity
- Low
- Confidentiality impact
- P
- Integrity impact
- P
- Availability impact
- P
Weakness class (CWE)
CWE-787 · Out-of-bounds WriteCVSS vector
AV:N/AC:L/Au:N/C:P/I:P/A:P
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
- lists.fedoraproject.org/pipermail/package-announce/2013-May/105176.html
- mailman.nginx.org/pipermail/nginx-announce/2013/000112.html
- nginx.org/download/patch.2013.chunked.txt
- secunia.com/advisories/55181
- security.gentoo.org/glsa/glsa-201310-04.xml
- www.osvdb.org/93037
- www.securityfocus.com/bid/59699
- www.vnsecurity.net/2013/05/analysis-of-nginx-cve-2013-2028/
- github.com/rapid7/metasploit-framework/pull/1834
Vendor advisories and official records. Exploit/PoC links are deliberately left out.