set_file_metadata in xattr.c in GNU Wget before 1.20.1 stores a file's origin URL in the user.xdg.origin.url metadata attribute of the extended attributes of the downloaded file, which allows local users to obtain sensitive information (e.g., credentials contained in the URL) by reading this attribute, as demonstrated by getfattr. This also applies to Referer information in the user.xdg.referrer.url metadata attribute. According to 2016-07-22 in the Wget ChangeLog, user.xdg.origin.url was partially based on the behavior of fwrite_xattr in tool_xattr.c in curl.
The MITRE CVE dictionary describes this issue as:
Find out more about CVE-2018-20483 from the MITRE CVE dictionary dictionary and NIST NVD.
NOTE: The following CVSS v3 metrics and score provided are preliminary and subject to review.
| CVSS3 Base Score | 5.5 |
|---|---|
| CVSS3 Base Metrics | CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N |
| Attack Vector | Local |
| Attack Complexity | Low |
| Privileges Required | None |
| User Interaction | Required |
| Scope | Unchanged |
| Confidentiality | High |
| Integrity Impact | None |
| Availability Impact | None |
| Platform | Package | State |
|---|---|---|
| Red Hat Enterprise Linux 7 | wget | Not affected |
| Red Hat Enterprise Linux 7 | curl | Will not fix |
| Red Hat Enterprise Linux 6 | wget | Not affected |
| Red Hat Enterprise Linux 6 | curl | Not affected |
| Red Hat Enterprise Linux 5 | curl | Not affected |
| Red Hat Enterprise Linux 5 | wget | Not affected |
wget users should pass credentials using the "--user/password" or the "--user/--ask-password" command line argument to wget or use --no-xattr to turn off saving extended attribute information. In curl downloading extended attributes is disabled by default.
Vulmon