Out-of-bounds Read in Freebsd Libfetch
CVE-2021-36159
libfetch before 2021-07-26, as used in apk-tools, xbps, and other products, mishandles numeric strings for the FTP and HTTP protocols. The FTP passive mode implementation allows an out-of-bounds read because strtol is used to parse the relevant numbers into address bytes. It does not check if the line ends prematurely. If it does, the for-loop condition checks for the '\0' terminator one byte too late.
Vulnerability class: Buffer Overflow
EPSS: 0.026 (84.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H.
Affected products
- Freebsd Libfetch
- N/a — versions n/a
Weakness classification (CWE)
Public proof-of-concept exploits
References
- cve@mitre.org (Exploit, Third Party Advisory, x_refsource_MISC)
- cve@mitre.org (Patch, Third Party Advisory, x_refsource_MISC)
- cve@mitre.org (mailing-list, x_refsource_MLIST)
- cve@mitre.org (mailing-list, x_refsource_MLIST)
- cve@mitre.org (mailing-list, x_refsource_MLIST)
- cve@mitre.org (mailing-list, x_refsource_MLIST)
Frequently asked questions
- What is CVE-2021-36159?
- CVE-2021-36159 is a critical-severity vulnerability in Freebsd Libfetch, classified under Out-of-bounds Read. CVSS score: 9.1/10. Published 2021-08-03.
- How severe is CVE-2021-36159?
- Critical severity. CVSS v3 base score is 9.1 out of 10.
- Is CVE-2021-36159 known to be exploited?
- 19 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.