NIXPKGS-2026-1953

GitHub issue published 2 hours ago

libssh2 - Heap Buffer Over-read via sftp_symlink() in sftp.c

Permalink CVE-2025-15661

8.3 HIGH

CVSS version (CVSS): 4.0
Attack Vector (AV): Network (N)
Attack Complexity (AC): High (H)
Attack Requirement (AT): None (N)
Privileges Required (PR): None (N)
User Interaction (UI): None (N)
Vulnerable System Impact Confidentiality (VC): Low (L)
Vulnerable System Impact Integrity (VI): None (N)
Vulnerable System Impact Availability (VA): High (H)
Subsequent System Impact Confidentiality (SC): None (N)
Subsequent System Impact Integrity (SI): None (N)
Subsequent System Impact Availability (SA): None (N)
Modified Attack Vector (MAV): Network (N)
Modified Attack Complexity (MAC): High (H)
Modified Attack Requirement (MAT): None (N)
Modified Privileges Required (MPR): None (N)
Modified User Interaction (MUI): None (N)
Modified Vulnerable System Impact Confidentiality (MVC): Low (L)
Modified Vulnerable System Impact Integrity (MVI): None (N)
Modified Vulnerable System Impact Availability (MVA): High (H)
Modified Subsequent System Impact Confidentiality (MSC): Negligible (N)
Modified Subsequent System Impact Integrity (MSI): Negligible (N)
Modified Subsequent System Impact Availability (MSA): Negligible (N)
Safety (S): Not Defined (X)
Automatable (AU): Not Defined (X)
Recovery (R): Not Defined (X)
Value Density (V): Not Defined (X)
Vulnerability Response Effort (RE): Not Defined (X)
Provider Urgency (U): Not Defined (X)
Confidentiality Req. (CR): Not Defined (X)
Integrity Req. (IR): Not Defined (X)
Availability Req. (AR): Not Defined (X)
Exploit Maturity (E): Not Defined (X)

updated 2 hours ago by @LeSuisse Activity log

Created suggestion 7 hours ago
@LeSuisse ignored
2 packages
- haskellPackages.libssh2
- haskellPackages.libssh2-conduit
2 hours ago
@LeSuisse ignored reference https://w… 2 hours ago
@LeSuisse accepted 2 hours ago
@LeSuisse published on GitHub 2 hours ago

libssh2 - Heap Buffer Over-read via sftp_symlink() in sftp.c

libssh2 through 1.11.1, fixed in commit 2dae302, contains an out-of-bounds heap read vulnerability in the sftp_symlink() function in src/sftp.c that allows a malicious SSH server or man-in-the-middle attacker to disclose heap memory contents or cause a crash by sending a crafted SSH_FXP_NAME response. Attackers can supply a link_len value larger than the actual packet data in SSH_FXP_NAME responses for SFTP READLINK and REALPATH operations, triggering a heap buffer over-read of up to target_len minus one bytes due to the missing validation of available packet buffer size before the memcpy operation.