CriticalFix available
apk-tools — security advisory
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.
- Products
- apk-tools
- Affected versions
- Not specified
- Fixed versions
- 2.10.7-r0, 2.12.6-r0
- CVEs
- CVE-2021-36159
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 22:05 UTC · Revision 1
Source evidence
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.
osv:ALPINE-CVE-2021-36159
apk-tools
Fixed versions: 2.10.7-r0
apk-tools
Fixed versions: 2.10.7-r0
apk-tools
Fixed versions: 2.10.7-r0
apk-tools
Fixed versions: 2.12.6-r0
apk-tools
Fixed versions: 2.12.6-r0
apk-tools
Fixed versions: 2.12.6-r0
apk-tools
Fixed versions: 2.12.6-r0
apk-tools
Fixed versions: 2.12.6-r0
apk-tools
Fixed versions: 2.12.6-r0
apk-tools
Fixed versions: 2.12.6-r0
apk-tools
Fixed versions: 2.12.6-r0
apk-tools
Fixed versions: 2.12.6-r0
apk-tools
Fixed versions: 2.12.6-r0
apk-tools
Fixed versions: 2.12.6-r0
apk-tools
Fixed versions: 2.12.6-r0
Complete source record
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"modified": "2026-10-23T17:17:56.198606684Z",
"provider": "osv",
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