1921768 - (CVE-2024-11705) SEGV in NSC_DeriveKey

Status: RESOLVED FIXED

(NSS :: Libraries, defect, P3)

Description

[coffeys]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/129.0.0.0 Safari/537.36

Steps to reproduce:

Called C_DeriveKey and passed NULL for phKey value:

NSC_DeriveKey(CK_SESSION_HANDLE hSession,
CK_MECHANISM_PTR pMechanism, CK_OBJECT_HANDLE hBaseKey,
CK_ATTRIBUTE_PTR pTemplate, CK_ULONG ulAttributeCount,
CK_OBJECT_HANDLE_PTR phKey)

Actual results:

SEGV due to libsoftokn3.so with NSS >= 3.103

libsoftokn3.so+0x305cd

issue in lib/softoken/pkcs11c.c

With recent code change in NSC_DeriveKey function, there's an assumption that phKey variable is non-NULL

https://github.com/nss-dev/nss/commit/9adf6e998915668f86d38436ed494ec7a468a9de#diff-02ad66dc66d5472ca33807f52cddf27086f41089d968a6a81e991577ed000abfR7392

Presuming it's non-NULL seems to be an issue. The PKCS#11 v3.0 current mechanism specification hints that phKey should be NULL for certain mechanisms :

"the parameter phKey passed to C_DeriveKey is unnecessary, and should be a NULL_PTR." under "2.39.6 Key and MAC derivation"

Comment 1

[John Schanck [:jschanck]]

Attachment: Bug 1921768 - allow null phKey in NSC_DeriveKey. r=rrelyea

Comment 2

[John Schanck [:jschanck]]

https://hg.mozilla.org/projects/nss/rev/9549d3d6d8ea9db8a28ae7e93e10478cd5272387

Comment 3

[Tom Ritter [:tjr] (OOTO until 9/2)]

Attachment: advisory.txt