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CVE-2026-89537: Linux

9.1

CVSS 3.1

Няма данни

Вероятност да бъде експлоатирана в следващите 30 дни (EPSS)

Няма потвърждение

Атакува се

Няма данни

Време до експлоатация

Атакува се по мрежата, без особени условия, без вход и без действие от потребителя.

  • Експлоатация: няма данни за експлоатация
  • Атаката може да се автоматизира

Описание

Оригинално описание

In the Linux kernel, the following vulnerability has been resolved: SUNRPC: Reject short RFC 4121 MIC tokens in gss_krb5_verify_mic_v2 gss_krb5_verify_mic_v2() reads the token ID at ptr[0..1], the flags byte at ptr[2], and padding at ptr[3..7], then passes ptr + GSS_KRB5_TOK_HDR_LEN and cksum_len to gss_krb5_mic_build_sg(). None of these accesses check read_token->len first. The minimum safe token size is GSS_KRB5_TOK_HDR_LEN (16) plus ctx->krb5e->cksum_len (12-24, depending on the enctype). All callers accept shorter tokens from the wire: - gss_unwrap_resp_integ() enforces only an upper bound (offset + len <= rcv_buf->len) before allocating mic.data = kmalloc(len) and passing it to gss_verify_mic(). A malicious NFS server can therefore supply a short checksum opaque, producing a small slab allocation that the Kerberos MIC verifier reads past. - gss_validate() enforces only len <= RPC_MAX_AUTH_SIZE (400) before passing the wire-supplied length to gss_validate_seqno_mic(), which constructs a mic xdr_netobj and calls gss_verify_mic(). - svcauth_gss_verify_header() enforces only checksum.len >= XDR_UNIT (4 bytes) before dispatching to gss_verify_mic(). - svcauth_gss_unwrap_integ() checks only that the checksum fits in gsd->gsd_scratch. Add a length guard at the top of gss_krb5_verify_mic_v2(), before any ptr[] access or scatterlist construction. Well-formed MIC tokens from gss_krb5_get_mic_v2() already have exactly GSS_KRB5_TOK_HDR_LEN + cksum_len bytes, so valid traffic is unaffected.

Засегнати продукти

  • Linux Linux: de9c17eb4a912c9028f7b470eb80815144883b26 преди 86c3d527303ec79805098bda3dfc4fa994757f59; de9c17eb4a912c9028f7b470eb80815144883b26 преди b2e9e10f5a536befcdce64d3e6946dff42fb823e; de9c17eb4a912c9028f7b470eb80815144883b26 преди 997577c52487181226775db3755079a3ba1d52b9; de9c17eb4a912c9028f7b470eb80815144883b26 преди 996dd15f60121bdd7896b4554458f8806d608063; de9c17eb4a912c9028f7b470eb80815144883b26 преди 7a946b2e7207f968902f2147ab9b30726f82f7ab; de9c17eb4a912c9028f7b470eb80815144883b26 преди b94f6719dcd9f7a609bc5f459f85795900e77d25
  • Linux Linux: 2.6.35; преди 2.6.35; 6.1.191 до 6.1.*; 6.6.160 до 6.6.*; 6.12.114 до 6.12.*; 6.18.57 до 6.18.*; 7.2.4 до 7.2.*; 7.3 до *

История

  • 11 септември 2026 Публикувано

Други уязвимости в Linux Linux

Първоизточници

CVE-2026-89537: Linux | freedomonline.bg