{"id":"CVE-2026-48693","state":"PUBLISHED","title":"FastNetMon Community Edition through 1.2.9 is vulnerable to a local symlink attack via predictable file paths in /tmp. The statistics file path defaults to '/tmp/fastnetmon.dat' (s","description":"FastNetMon Community Edition through 1.2.9 is vulnerable to a local symlink attack via predictable file paths in /tmp. The statistics file path defaults to '/tmp/fastnetmon.dat' (src/fastnetmon.cpp line 159). The print_screen_contents_into_file() function (src/fastnetmon_logic.cpp line 2186) opens this path with std::ios::trunc without checking for symlinks or using O_NOFOLLOW. Additionally, the chmod() call on line 2190 always operates on cli_stats_file_path regardless of which file_path parameter was passed (a bug that applies wrong permissions), and the umask is set to 0 during daemonization (src/fastnetmon.cpp line 1821), making all created files world-writable. A local attacker can exploit this to overwrite arbitrary files as the FastNetMon process user (typically root).","publishedAt":"2026-05-26T00:00:00.000Z","updatedAt":"2026-05-26T20:33:37.827Z","severity":{"score":5.5,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","source":"CISA-ADP"},"assigner":"mitre","products":["n/a n/a"],"affected":[{"vendor":"n/a","product":"n/a","versions":[{"version":"n/a","status":"affected"}]}],"references":["https://github.com/pavel-odintsov/fastnetmon","https://github.com/pavel-odintsov/fastnetmon/blob/master/src/fastnetmon.cpp","https://github.com/pavel-odintsov/fastnetmon/blob/master/src/fastnetmon_logic.cpp","https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48693-symlink-tmp"],"weaknesses":["CWE-59"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/48xxx/CVE-2026-48693.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-48693","state":"PUBLISHED","datePublished":"2026-05-26T00:00:00.000Z","dateUpdated":"2026-05-26T20:33:37.827Z","assignerShortName":"mitre","assignerOrgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","dateReserved":"2026-05-22T00:00:00.000Z"},"containers":{"cna":{"descriptions":[{"lang":"en","value":"FastNetMon Community Edition through 1.2.9 is vulnerable to a local symlink attack via predictable file paths in /tmp. The statistics file path defaults to '/tmp/fastnetmon.dat' (src/fastnetmon.cpp line 159). The print_screen_contents_into_file() function (src/fastnetmon_logic.cpp line 2186) opens this path with std::ios::trunc without checking for symlinks or using O_NOFOLLOW. Additionally, the chmod() call on line 2190 always operates on cli_stats_file_path regardless of which file_path parameter was passed (a bug that applies wrong permissions), and the umask is set to 0 during daemonization (src/fastnetmon.cpp line 1821), making all created files world-writable. A local attacker can exploit this to overwrite arbitrary files as the FastNetMon process user (typically root)."}],"affected":[{"vendor":"n/a","product":"n/a","versions":[{"version":"n/a","status":"affected"}]}],"references":[{"url":"https://github.com/pavel-odintsov/fastnetmon"},{"url":"https://github.com/pavel-odintsov/fastnetmon/blob/master/src/fastnetmon.cpp"},{"url":"https://github.com/pavel-odintsov/fastnetmon/blob/master/src/fastnetmon_logic.cpp"},{"url":"https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48693-symlink-tmp"}],"problemTypes":[{"descriptions":[{"type":"text","lang":"en","description":"n/a"}]}],"providerMetadata":{"shortName":"mitre","orgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","dateUpdated":"2026-05-26T16:48:45.595Z"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":5.5,"attackVector":"LOCAL","baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","integrityImpact":"HIGH","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"NONE","privilegesRequired":"LOW","confidentialityImpact":"NONE"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-05-26T20:33:34.242754Z","id":"CVE-2026-48693","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-59","type":"CWE","lang":"en","description":"CWE-59 Improper Link Resolution Before File Access ('Link Following')"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-05-26T20:33:37.827Z"}}]}}}