CVE-2023-38545This flaw makes curl overflow a heap based buffer in the SOCKS5 proxy handshake. When curl is asked to pass along the host name to the…
- 8.8HighCVSS base score
- 78.3%Exploitation in 30 daysEPSS · top 0.4% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
Description
This flaw makes curl overflow a heap based buffer in the SOCKS5 proxy handshake. When curl is asked to pass along the host name to the SOCKS5 proxy to allow that to resolve the address instead of it getting done by curl itself, the maximum length that host name can be is 255 bytes. If the host name is detected to be longer, curl switches to local name resolving and instead passes on the resolved address only. Due to this bug, the local variable that means "let the host resolve the name" could get the wrong value during a slow SOCKS5 handshake, and contrary to the intention, copy the too long host name to the target buffer instead of copying just the resolved address there. The target buffer being a heap based buffer, and the host name coming from the URL that curl has been told to operate with.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. 3 references of the record are tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits3
References tagged exploit3 references
Timeline
ID reserved
By hackerone
- 3 months later
· 3 months later
Published
- 3 years later
· 3 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 |
|---|---|---|---|
| CISA-ADPADP (enrichment) | 3.1 | High8.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 78.3% · top 0.4% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.8.
Affected products
References
References21
- https://curl.se/docs/CVE-2023-38545.html (opens in a new tab)x_transferred
- https://security.netapp.com/advisory/ntap-20231027-0009/ (opens in a new tab)x_transferred
- https://lists.fedoraproject.org/archives/list/[email protected]/message/OGMXNRNSJ4ETDK6FRNU3J7SABXPWCHSQ/ (opens in a new tab)x_transferred
- https://www.secpod.com/blog/high-severity-heap-buffer-overflow-vulnerability/ (opens in a new tab)x_transferred
- https://support.apple.com/kb/HT214036 (opens in a new tab)x_transferred
- https://support.apple.com/kb/HT214063 (opens in a new tab)x_transferred
- https://support.apple.com/kb/HT214057 (opens in a new tab)x_transferred
- https://support.apple.com/kb/HT214058 (opens in a new tab)x_transferred
- http://seclists.org/fulldisclosure/2024/Jan/34 (opens in a new tab)x_transferred
- http://seclists.org/fulldisclosure/2024/Jan/37 (opens in a new tab)x_transferred
- http://seclists.org/fulldisclosure/2024/Jan/38 (opens in a new tab)x_transferred
- https://security.netapp.com/advisory/ntap-20240201-0005/ (opens in a new tab)x_transferred
- https://forum.vmssoftware.com/viewtopic.php?f=8&t=8868 (opens in a new tab)x_transferred
- https://github.com/bcdannyboy/CVE-2023-38545 (opens in a new tab)exploit
- https://github.com/dbrugman/CVE-2023-38545-POC (opens in a new tab)exploit
- https://github.com/UTsweetyfish/CVE-2023-38545 (opens in a new tab)exploit
- https://cert-portal.siemens.com/productcert/html/ssa-943925.html (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-832273.html (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-093430.html (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-507364.html (opens in a new tab)
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-2023-42344 (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-2023-38545)Record last updated .