Information disclosure in Haxx Libcurl
CVE-2017-1000100
When doing a TFTP transfer and curl/libcurl is given a URL that contains a very long file name (longer than about 515 bytes), the file name is truncated to fit within the buffer boundaries, but the buffer size is still wrongly updated to use the untruncated length. This too large value is then used in the sendto() call, making curl attempt to send more data than what is actually put into the buffer. The endto() function will then read beyond the end of the heap based buffer. A malicious HTTP(S) server could redirect a vulnerable libcurl-using client to a crafted TFTP URL (if the client hasn't restricted which protocols it allows redirects to) and trick it to send private memory contents to a remote server over UDP. Limit curl's redirect protocols with --proto-redir and libcurl's with CURLOPT_REDIR_PROTOCOLS.
Vulnerability class: Information Disclosure
EPSS: 0.040 (89.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.
Affected products
- Haxx Libcurl — versions 7.15.0, 7.15.1, 7.15.2
- N/a — versions n/a
Weakness classification (CWE)
Public proof-of-concept exploits
References
- cve@mitre.org (x_refsource_CONFIRM)
- cve@mitre.org (VDB Entry, Third Party Advisory, vdb-entry, x_refsource_BID)
- cve@mitre.org (x_refsource_REDHAT, vendor-advisory)
- cve@mitre.org (vendor-advisory, Patch, VDB Entry, Third Party Advisory, x_refsource_GENTOO)
- cve@mitre.org (VDB Entry, Third Party Advisory, vdb-entry, x_refsource_SECTRACK)
- cve@mitre.org (x_refsource_CONFIRM, Patch, Vendor Advisory)
- cve@mitre.org (vendor-advisory, x_refsource_DEBIAN)
Frequently asked questions
- What is CVE-2017-1000100?
- CVE-2017-1000100 is a medium-severity vulnerability in Haxx Libcurl, classified under Information Disclosure. CVSS score: 6.5/10. Published 2017-10-05.
- How severe is CVE-2017-1000100?
- Medium severity. CVSS v3 base score is 6.5 out of 10.
- Is CVE-2017-1000100 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.