FreeBSD VuXML: Documenting security issues in FreeBSD and the FreeBSD Ports Collection

curl -- multiple vulnerabilities

Affected packages
curl < 7.64.0


VuXML ID 714b033a-2b09-11e9-8bc3-610fd6e6cd05
Discovery 2019-02-07
Entry 2019-02-07

curl security problems:

CVE-2018-16890: NTLM type-2 out-of-bounds buffer read

libcurl contains a heap buffer out-of-bounds read flaw.

The function handling incoming NTLM type-2 messages (lib/vauth/ntlm.c:ntlm_decode_type2_target) does not validate incoming data correctly and is subject to an integer overflow vulnerability.

Using that overflow, a malicious or broken NTLM server could trick libcurl to accept a bad length + offset combination that would lead to a buffer read out-of-bounds.

CVE-2019-3822: NTLMv2 type-3 header stack buffer overflow

libcurl contains a stack based buffer overflow vulnerability.

The function creating an outgoing NTLM type-3 header (lib/vauth/ntlm.c:Curl_auth_create_ntlm_type3_message()), generates the request HTTP header contents based on previously received data. The check that exists to prevent the local buffer from getting overflowed is implemented wrongly (using unsigned math) and as such it does not prevent the overflow from happening.

This output data can grow larger than the local buffer if very large "nt response" data is extracted from a previous NTLMv2 header provided by the malicious or broken HTTP server.

Such a "large value" needs to be around 1000 bytes or more. The actual payload data copied to the target buffer comes from the NTLMv2 type-2 response header.

CVE-2019-3823: SMTP end-of-response out-of-bounds read

libcurl contains a heap out-of-bounds read in the code handling the end-of-response for SMTP.

If the buffer passed to smtp_endofresp() isn't NUL terminated and contains no character ending the parsed number, and len is set to 5, then the strtol() call reads beyond the allocated buffer. The read contents will not be returned to the caller.


CVE Name CVE-2018-16890
CVE Name CVE-2019-3822
CVE Name CVE-2019-3823