CVE-2009-2473
neon before 0.28.6, when expat is used, does not properly detect recursion during entity expansion, which allows context-dependent…
- 4.3MediumCVSS base score
- 8.4%Exploitation in 30 daysEPSS · top 4.9% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- 1Public exploitsMetasploit, Nuclei and Exploit-DB
Description
neon before 0.28.6, when expat is used, does not properly detect recursion during entity expansion, which allows context-dependent attackers to cause a denial of service (memory and CPU consumption) via a crafted XML document containing a large number of nested entity references, a similar issue to CVE-2003-1564.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. The public collections list an Exploit-DB entry for it.
Show the exploits1
Exploit-DB1 entry
- Expat 2.0.1 - UTF-8 Character XML Parsing Remote Denial of Service (Exploit-DB entry) (opens in a new tab)
EDB-ID 10206dos, linuxpublished 12 Nov 2009Verified
Modules, templates and exploits as listed by the Metasploit Framework (BSD-3-Clause), ProjectDiscovery's Nuclei templates (MIT) and the Exploit Database (GPLv2), read once a day. Where the data comes from
Timeline
ID reserved
By redhat
- 37 days later
· 37 days later
Published
- 15 years later
· 15 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 2.0 | Medium4.3 | AV:N/AC:M/Au:N/C:N/I:N/A:P |
- EPSS (exploitation in 30 days)
- 8.4% · top 4.9% of all CVEs (11 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 4.3.
Affected products
n/a
- affected n/a
References
13
- [neon] 20090818 neon: release 0.28.6 (SECURITY) (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- oval:org.mitre.oval:def:9461 (opens in a new tab)vdb-entrysignaturex_refsource_OVALx_transferred
- http://support.apple.com/kb/HT4435 (opens in a new tab)x_refsource_CONFIRMx_transferred
- SUSE-SR:2009:018 (opens in a new tab)vendor-advisoryx_refsource_SUSEx_transferred
- ADV-2009-2341 (opens in a new tab)vdb-entryx_refsource_VUPENx_transferred
- MDVSA-2009:221 (opens in a new tab)vendor-advisoryx_refsource_MANDRIVAx_transferred
- APPLE-SA-2010-11-10-1 (opens in a new tab)vendor-advisoryx_refsource_APPLEx_transferred
- RHSA-2013:0131 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- 36371 (opens in a new tab)third-party-advisoryx_refsource_SECUNIAx_transferred
- FEDORA-2009-8815 (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- FEDORA-2009-8794 (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- neon-xml-dos(52633) (opens in a new tab)vdb-entryx_refsource_XFx_transferred
- [neon] 20090818 CVE-2009-2473: fix for "billion laughs" attack against expat (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2009-2468 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2009-2473)Record last updated .