csirt@kutim:~/threat-intel/cve/CVE-2021-3634

Katalog CVE

CVSS 6.5 · Medium EPSS 4,7%

Kerentanan Out-of-bounds Write pada libssh, redhat virtualization +5 lainnya. Skor CVSS 3.1 6.5 (Medium) menurut NVD.

Deskripsi (NVD)

A flaw has been found in libssh in versions prior to 0.9.6. The SSH protocol keeps track of two shared secrets during the lifetime of the session. One of them is called secret_hash and the other session_id. Initially, both of them are the same, but after key re-exchange, previous session_id is kept and used as an input to new secret_hash. Historically, both of these buffers had shared length variable, which worked as long as these buffers were same. But the key re-exchange operation can also change the key exchange method, which can be based on hash of different size, eventually creating "secret_hash" of different size than the session_id has. This becomes an issue when the session_id memory is zeroed or when it is used again during second key re-exchange.

Rincian

Terbit di NVD
31 Agustus 2021
Terakhir diubah
17 Juni 2026
Status NVD
Modified
CVSS 3.1
6.5 (Medium), sumber NVD
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H · uraikan di kalkulator
Jenis kelemahan (CWE)
CWE-787: Out-of-bounds Write
EPSS (30 hari)
4,7% peluang dieksploitasi; lebih tinggi dari 91,5% CVE lain

Produk dan versi terdampak

VendorProdukVersi terdampak
libssh libssh Versi 0.9.1 hingga sebelum 0.9.6
redhat virtualization Versi 4.0
redhat enterprise linux Versi 8.0
debian debian linux Versi 10.0
debian debian linux Versi 11.0
fedoraproject fedora Versi 33
fedoraproject fedora Versi 34
fedoraproject fedora Versi 35
oracle mysql workbench Semua versi hingga 8.0.27
netapp cloud backup Semua versi

> Data dari konfigurasi CPE di NVD.

Referensi dan perbaikan

Sumber: NVD · CVE.org · EPSS. Halaman ini disusun otomatis dari data tersebut; pembaruan terakhir 5 Okt 2026, 20:10 WITA. Kalau sistem di Perangkat Daerah memakai produk ini dan butuh bantuan, laporkan lewat kanal pelaporan.