In Heimdal through 7.4, remote unauthenticated attackers are able to crash the KDC by sending a crafted UDP packet containing empty data fields for client name or realm. The parser would unconditionally dereference NULL pointers in that case, leading to a segmentation fault. This is related to the _kdc_as_rep function in kdc/kerberos5.c and the der_length_visible_string function in lib/asn1/der_length.c.
総合評価: CVE-2017-17439 は中リスク（60.7/100）。CVSS 深刻度は高。悪用される可能性が高い（EPSS 3.78%、88 パーセンタイル） 推奨対応: 影響資産を整理し、修補計画に組み込んでください。
リスクは変動します。再評価に基づき、本ページの表示内容を更新しています。
EPSS は日次で悪用されやすさの相対度合いを推定します。パーセンタイルは採点済み CVE の中での相対位置（高いほど相対的に深刻）を示します。
| # | 日付 | 旧 EPSS スコア | 新 EPSS スコア | Δ（新 − 旧） |
|---|---|---|---|---|
| 1 | 2026-05-31 | 3.99% | 3.78% | -0.21% |
| 2 | 2026-04-05 | 9.18% | 3.99% | -5.19% |
| 3 | 2025-09-27 | — | 9.18% | — |
EPSS の全履歴 （全 14 件）
この CVE の CVSS 指標。
| ベーススコア | バージョン | 深刻度 | ベクトル | 悪用しやすさ | 影響 | スコアの出典 |
|---|---|---|---|---|---|---|
| 7.5 | 3.0 | HIGH |
|
3.9 | 3.6 | [email protected] |
| 5.0 | 2.0 | MEDIUM |
|
10.0 | 2.9 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
alpine
|
— | CVE-2017-17439: 1 source package rows (heimdal); 10 state rows across 10 repos (3.10-main, 3.11-main, 3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 10, open 0. | https://security.alpinelinux.org/vuln/CVE-2017-17439 |
debian
|
not yet assigned | CVE-2017-17439 not yet assigned priority: Debian including 1 source packages (heimdal), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. | https://security-tracker.debian.org/tracker/CVE-2017-17439 |
ubuntu
|
medium | CVE-2017-17439 medium priority: Ubuntu including 1 source packages (heimdal), 7 status rows across 7 suites (artful, bionic, cosmic, trusty, upstream, xenial, zesty): not-affected 4, ignored 2, released 1. | https://ubuntu.com/security/CVE-2017-17439 |
| ベンダー | 製品 | バージョン | 生の CPE |
|---|---|---|---|
| debian | debian_linux | 9.0 | cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* |
| heimdal_project | heimdal | <= 7.4.0 | cpe:2.3:a:heimdal_project:heimdal:*:*:*:*:*:*:*:* |
| URL | タグ |
|---|---|
| http://h5l.org/advisories.html?show=2017-12-08 | |
| http://www.h5l.org/pipermail/heimdal-announce/2017-December/000008.html | |
| http://www.h5l.org/pipermail/heimdal-discuss/2017-August/000259.html | Third Party Advisory |
| https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=878144 | Issue Tracking Mailing List Third Party Advisory |
| https://github.com/heimdal/heimdal/commit/1a6a6e462dc2ac6111f9e02c6852ddec4849b887 | Third Party Advisory |
| https://github.com/heimdal/heimdal/issues/353 | Patch Third Party Advisory |
| https://www.debian.org/security/2017/dsa-4055 | Third Party Advisory |