{"id":"CVE-2021-20285","aliases":["ALPINE-CVE-2021-20285","BELL-CVE-2021-20285","DEBIAN-CVE-2021-20285","EUVD-2021-7713","GHSA-9235-qgm5-877x","MGASA-2021-0241","UBUNTU-CVE-2021-20285","openSUSE-SU-2023:0088-1"],"status":"published","title":"A flaw was found in upx canPack in p_lx_elf.cpp in UPX 3.96. This flaw allows attackers to cause...","description":"A flaw was found in upx canPack in p_lx_elf.cpp in UPX 3.96. This flaw allows attackers to cause a denial of service (SEGV or buffer overflow and application crash) or possibly have unspecified other impacts via a crafted ELF. The highest threat from this vulnerability is to system availability.","severity":{"version":"3.1","score":6.6,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H","level":"medium","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-12","score":0.00751,"percentile":0.55491,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-119","CWE-787"],"published":"2021-03-26T16:35:14Z","modified":"2026-11-03T06:32:26Z","fixes":[{"ecosystem":"Alpine:v3.13","package":"upx","fixed_in":["3.96-r1"],"sources":["osv"]},{"ecosystem":"Alpine:v3.14","package":"upx","fixed_in":["3.96-r1"],"sources":["osv"]},{"ecosystem":"Alpine:v3.15","package":"upx","fixed_in":["3.96-r1"],"sources":["osv"]},{"ecosystem":"Alpine:v3.16","package":"upx","fixed_in":["3.96-r1"],"sources":["osv"]},{"ecosystem":"Alpine:v3.17","package":"upx","fixed_in":["3.96-r1"],"sources":["osv"]},{"ecosystem":"Alpine:v3.18","package":"upx","fixed_in":["3.96-r1"],"sources":["osv"]},{"ecosystem":"Alpine:v3.19","package":"upx","fixed_in":["3.96-r1"],"sources":["osv"]},{"ecosystem":"Alpine:v3.20","package":"upx","fixed_in":["3.96-r1"],"sources":["osv"]},{"ecosystem":"Alpine:v3.21","package":"upx","fixed_in":["3.96-r1"],"sources":["osv"]},{"ecosystem":"Alpine:v3.22","package":"upx","fixed_in":["3.96-r1"],"sources":["osv"]},{"ecosystem":"Alpine:v3.23","package":"upx","fixed_in":["3.96-r1"],"sources":["osv"]},{"ecosystem":"Alpine:v3.24","package":"upx","fixed_in":["3.96-r1"],"sources":["osv"]},{"ecosystem":"Debian:13","package":"upx-ucl","fixed_in":["4.2.2-1"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"upx-ucl","fixed_in":["4.2.2-1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Alpine:v3.13","package":"upx","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.96-r1"}]}]},{"source":"osv","ecosystem":"Alpine:v3.14","package":"upx","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.96-r1"}]}]},{"source":"osv","ecosystem":"Alpine:v3.15","package":"upx","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.96-r1"}]}]},{"source":"osv","ecosystem":"Alpine:v3.16","package":"upx","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.96-r1"}]}]},{"source":"osv","ecosystem":"Alpine:v3.17","package":"upx","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.96-r1"}]}]},{"source":"osv","ecosystem":"Alpine:v3.18","package":"upx","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.96-r1"}]}]},{"source":"osv","ecosystem":"Alpine:v3.19","package":"upx","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.96-r1"}]}]},{"source":"osv","ecosystem":"Alpine:v3.20","package":"upx","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.96-r1"}]}]},{"source":"osv","ecosystem":"Alpine:v3.21","package":"upx","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.96-r1"}]}]},{"source":"osv","ecosystem":"Alpine:v3.22","package":"upx","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.96-r1"}]}]},{"source":"osv","ecosystem":"Alpine:v3.23","package":"upx","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.96-r1"}]}]},{"source":"osv","ecosystem":"Alpine:v3.24","package":"upx","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.96-r1"}]}]},{"source":"osv","ecosystem":"Debian:13","package":"upx-ucl","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.2.2-1"}]}]},{"source":"osv","ecosystem":"Debian:14","package":"upx-ucl","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.2.2-1"}]}]},{"source":"osv","ecosystem":"Mageia:7","package":"upx","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.96-1.1.mga7"}]}],"bundled":2},{"source":"osv","ecosystem":"Mageia:8","package":"upx","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.96-2.1.mga8"}]}],"bundled":2},{"source":"osv","ecosystem":"Ubuntu:16.04:LTS","package":"upx-ucl","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.91-1"]},{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"upx-ucl","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.94-2","3.94-3","3.94-4"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"upx-ucl","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.95-2","3.95-2build1"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"upx-ucl","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.96-2","3.96-3"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"upx-ucl","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.96-3","4.2.2-3"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"upx-ucl","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.2.4-1","4.2.4-1.1"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"upx-ucl","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.2.4-1.1build1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"upx-ucl","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.2.4-1.1","4.2.4-1.1build1"]},{"source":"osv","ecosystem":"SUSE:Package Hub 15 SP4","package":"upx","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.0.2-bp154.4.6.1"}]}],"bundled":12},{"source":"osv","ecosystem":"openSUSE:Leap 15.4","package":"upx","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.0.2-bp154.4.6.1"}]}],"bundled":12}],"products":[{"vendor":"upx","product":"upx"}],"references":[{"url":"https://github.com/upx/upx/issues/421","tags":["x_refsource_MISC","x_transferred","Exploit","Issue Tracking","Third Party Advisory","report"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=1937787","tags":["x_refsource_MISC","x_transferred","Issue Tracking","Third Party Advisory","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-20285"},{"url":"https://github.com/advisories/GHSA-9235-qgm5-877x"},{"url":"https://security.alpinelinux.org/vuln/CVE-2021-20285","tags":["advisory"]},{"url":"https://docs.bell-sw.com/security/cves/CVE-2021-20285","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2021-20285","tags":["advisory"]},{"url":"https://advisories.mageia.org/MGASA-2021-0241.html","tags":["advisory"]},{"url":"https://bugs.mageia.org/show_bug.cgi?id=29016","tags":["report"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/thread/G3BQABK4YLXENDJBLDMHAIPRTC3ZMLYK/","tags":["web"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/thread/VSQRO7YC72PSYDQG4PQLQYXZTZE3B4YV/","tags":["web"]},{"url":"https://lists.opensuse.org/archives/list/security-announce@lists.opensuse.org/thread/V2GCFGL5HHPU3GIC7XYIPIMYFFLH2M4U/","tags":["web"]},{"url":"https://ubuntu.com/security/CVE-2021-20285","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-20285","tags":["report"]},{"url":"https://lists.opensuse.org/archives/list/security-announce@lists.opensuse.org/thread/XLSYENIWX7YMHJJKVRBH2CPDXM5X3IW6/","tags":["advisory"]},{"url":"https://bugzilla.suse.com/1183510","tags":["report"]},{"url":"https://bugzilla.suse.com/1184701","tags":["report"]},{"url":"https://bugzilla.suse.com/1184702","tags":["report"]},{"url":"https://bugzilla.suse.com/1207121","tags":["report"]},{"url":"https://bugzilla.suse.com/1207122","tags":["report"]},{"url":"https://bugzilla.suse.com/1209765","tags":["report"]},{"url":"https://bugzilla.suse.com/1209766","tags":["report"]},{"url":"https://bugzilla.suse.com/1209767","tags":["report"]},{"url":"https://bugzilla.suse.com/1209768","tags":["report"]},{"url":"https://bugzilla.suse.com/1209769","tags":["report"]},{"url":"https://bugzilla.suse.com/1209770","tags":["report"]},{"url":"https://bugzilla.suse.com/1209771","tags":["report"]},{"url":"https://www.suse.com/security/cve/CVE-2021-20285","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2021-30500","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2021-30501","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2021-43311","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2021-43312","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2021-43313","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2021-43314","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2021-43315","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2021-43316","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2021-43317","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2023-23456","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2023-23457","tags":["web"]}],"sources":{"cve":[{"id":"CVE-2021-20285","description":"A flaw was found in upx canPack in p_lx_elf.cpp in UPX 3.96. This flaw allows attackers to cause a denial of service (SEGV or buffer overflow and application crash) or possibly have unspecified other impacts via a crafted ELF. The highest threat from this vulnerability is to system availability.","status":"published","published":"2021-03-26T16:35:14Z","modified":"2024-08-03T17:37:22.715Z","cwes":["CWE-119"],"updated_at":"2026-11-02T14:32:55.905855Z"}],"euvd":[{"id":"EUVD-2021-7713","description":"A flaw was found in upx canPack in p_lx_elf.cpp in UPX 3.96. This flaw allows attackers to cause a denial of service (SEGV or buffer overflow and application crash) or possibly have unspecified other impacts via a crafted ELF. The highest threat from this vulnerability is to system availability.","status":"published","published":"2021-03-26T16:35:14Z","modified":"2024-08-03T17:37:22Z","updated_at":"2026-11-03T03:25:09.355483Z"}],"ghsa":[{"id":"GHSA-9235-qgm5-877x","title":"A flaw was found in upx canPack in p_lx_elf.cpp in UPX 3.96. This flaw allows attackers to cause...","description":"A flaw was found in upx canPack in p_lx_elf.cpp in UPX 3.96. This flaw allows attackers to cause a denial of service (SEGV or buffer overflow and application crash) or possibly have unspecified other impacts via a crafted ELF. The highest threat from this vulnerability is to system availability.","status":"published","published":"2022-05-24T17:45:32Z","modified":"2023-01-27T05:03:30Z","cvss":[{"version":"3.1","score":6.6,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H","level":"medium"}],"cwes":["CWE-119","CWE-787"],"updated_at":"2026-11-02T14:42:15.698999Z"}],"nvd":[{"id":"CVE-2021-20285","description":"A flaw was found in upx canPack in p_lx_elf.cpp in UPX 3.96. This flaw allows attackers to cause a denial of service (SEGV or buffer overflow and application crash) or possibly have unspecified other impacts via a crafted ELF. The highest threat from this vulnerability is to system availability.","status":"published","published":"2021-03-26T17:15:13.14Z","modified":"2026-06-17T03:33:36.467Z","cvss":[{"version":"3.1","score":6.6,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H","level":"medium","assessor":"primary"},{"version":"2.0","score":8.3,"vector":"AV:N/AC:M/Au:N/C:P/I:P/A:C","level":"high","assessor":"primary"}],"cwes":["CWE-119","CWE-787"],"updated_at":"2026-11-02T14:06:51.197859Z"}],"osv":[{"id":"ALPINE-CVE-2021-20285","description":"A flaw was found in upx canPack in p_lx_elf.cpp in UPX 3.96. This flaw allows attackers to cause a denial of service (SEGV or buffer overflow and application crash) or possibly have unspecified other impacts via a crafted ELF. The highest threat from this vulnerability is to system availability.","status":"published","published":"2021-03-26T17:15:13.14Z","modified":"2026-11-03T06:32:26.95930785Z","cvss":[{"version":"3.1","score":6.6,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H","level":"medium"}],"updated_at":"2026-11-03T07:17:57.723967Z"},{"id":"BELL-CVE-2021-20285","title":"CVE-2021-20285 does not affect BellSoft software","status":"withdrawn","published":"2023-08-31T12:13:21.97897Z","modified":"2026-01-26T09:49:54.180387Z","cvss":[{"version":"3.1","score":6.6,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H","level":"medium"}],"updated_at":"2026-11-02T15:28:15.925958Z"},{"id":"CVE-2021-20285","description":"A flaw was found in upx canPack in p_lx_elf.cpp in UPX 3.96. This flaw allows attackers to cause a denial of service (SEGV or buffer overflow and application crash) or possibly have unspecified other impacts via a crafted ELF. The highest threat from this vulnerability is to system availability.","status":"published","published":"2021-03-26T17:15:13.14Z","modified":"2026-10-20T10:53:32.89252285Z","cvss":[{"version":"3.1","score":6.6,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H","level":"medium"}],"updated_at":"2026-11-02T15:44:18.004149Z"},{"id":"DEBIAN-CVE-2021-20285","description":"A flaw was found in upx canPack in p_lx_elf.cpp in UPX 3.96. This flaw allows attackers to cause a denial of service (SEGV or buffer overflow and application crash) or possibly have unspecified other impacts via a crafted ELF. The highest threat from this vulnerability is to system availability.","status":"published","published":"2021-03-26T17:15:13.14Z","modified":"2026-10-23T18:03:10.427897857Z","cvss":[{"version":"3.1","score":6.6,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H","level":"medium"}],"updated_at":"2026-11-02T15:45:34.637046Z"},{"id":"UBUNTU-CVE-2021-20285","description":"A flaw was found in upx canPack in p_lx_elf.cpp in UPX 3.96. This flaw allows attackers to cause a denial of service (SEGV or buffer overflow and application crash) or possibly have unspecified other impacts via a crafted ELF. The highest threat from this vulnerability is to system availability.","status":"published","published":"2021-03-26T17:15:00Z","modified":"2026-10-17T12:56:19.174889645Z","cvss":[{"version":"3.1","score":6.6,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H","level":"medium"}],"updated_at":"2026-11-02T15:54:25.728622Z"},{"id":"MGASA-2021-0241","title":"Updated upx packages fix security vulnerabilities","description":"The updated package fixes security vulnerabilities:\n\nA heap buffer overflow read was discovered in upx 4.0.0, because the\ncheck in p_lx_elf.cpp is not perfect. (CVE-2020-24119)\n\nA flaw was found in upx canPack in p_lx_elf.cpp in UPX 3.96. This flaw\nallows attackers to cause a denial of service (SEGV or buffer overflow\nand application crash) or possibly have unspecified other impacts via a\ncrafted ELF. The highest threat from this vulnerability is to system\navailability. (CVE-2021-20285)\n","status":"published","published":"2021-06-08T16:46:03Z","modified":"2026-04-16T04:41:55.45782854Z","updated_at":"2026-11-02T15:49:41.509337Z"},{"id":"openSUSE-SU-2023:0088-1","title":"Security update for upx","description":"\nupx was updated to fix the following issues:\n\nUpdate to release 4.0.2\n\n* Fix unpack of ELF x86-64 that failed with 'CantUnpackException: corrupt b_info'\n* Resolve SEGV on PackLinuxElf64::invert_pt_dynamic\n\n- CVE-2021-30500: Fixed Null pointer dereference in PackLinuxElf:canUnpack() in p_lx_elf.cpp\n- CVE-2021-30501: Fixed Assertion abort in function MemBuffer:alloc()\n- CVE-2021-43311: Fixed Heap-based buffer overflow in PackLinuxElf32:elf_lookup() at p_lx_elf.cpp\n- CVE-2021-43312: Fixed Heap-based buffer overflow in PackLinuxElf64:invert_pt_dynamic at p_lx_elf.cpp:5239\n- CVE-2021-43313: Fixed Heap-based buffer overflow in PackLinuxElf32:invert_pt_dynamic at p_lx_elf.cpp:1688\n- CVE-2021-43314: Fixed Heap-based buffer overflows in PackLinuxElf32:elf_lookup() at p_lx_elf.cp\n- CVE-2021-43315: Fixed Heap-based buffer overflows in PackLinuxElf32:elf_lookup() at p_lx_elf.cp\n- CVE-2021-43316: Fixed Heap-based buffer overflow in func get_le64()\n- CVE-2021-43317: Fixed Heap-based buffer overflows in PackLinuxElf64:elf_lookup() at p_lx_elf.cp\n- CVE-2023-23456: Fixed heap-buffer-overflow in PackTmt:pack()\n- CVE-2023-23457: Fixed SEGV on PackLinuxElf64:invert_pt_dynamic() in p_lx_elf.cpp\n","status":"published","published":"2023-04-11T07:07:29Z","modified":"2025-05-07T18:12:22.423988Z","updated_at":"2026-11-02T16:58:32.653274Z"}]}}