The remote Debian host is missing a security-related update.
Multiple vulnerabilities were discovered in cURL, an URL transfer library. - CVE-2018-1000120 Duy Phan Thanh discovered that curl could be fooled into writing a zero byte out of bounds when curl is told to work on an FTP URL with the setting to only issue a single CWD command, if the directory part of the URL contains a '%00' sequence. - CVE-2018-1000121 Dario Weisser discovered that curl might dereference a near-NULL address when getting an LDAP URL due to the ldap_get_attribute_ber() function returning LDAP_SUCCESS and a NULL pointer. A malicious server might cause libcurl-using applications that allow LDAP URLs, or that allow redirects to LDAP URLs to crash. - CVE-2018-1000122 OSS-fuzz, assisted by Max Dymond, discovered that curl could be tricked into copying data beyond the end of its heap based buffer when asked to transfer an RTSP URL.
Upgrade the curl packages. For the oldstable distribution (jessie), these problems have been fixed in version 7.38.0-4+deb8u10. For the stable distribution (stretch), these problems have been fixed in version 7.52.1-5+deb9u5.