SB2019112101 - FortiOS update for libssh2
Published: November 21, 2019
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 9 secuirty vulnerabilities.
1) Out-of-bounds read (CVE-ID: CVE-2019-3861)
The vulnerability allows a remote attacker to gain access to potentially sensitive information or perform denial of service (DoS) attack.
The vulnerability exists due to a boundary condition when SSH packets with a padding length value greater than the packet length are parsed. A remote attacker can trick the victim to connect to a malicious SSH server, trigger out of bounds read and gain access to sensitive information or perform denial of service attack.
2) Out-of-bounds read (CVE-ID: CVE-2019-3862)
The vulnerability allows a remote attacker to gain access to potentially sensitive information or perform denial of service (DoS) attack.
The vulnerability exists due to a boundary condition when SSH_MSG_CHANNEL_REQUEST packets with an exit status message and no payload are parsed. A remote attacker can trick the victim to connect to a malicious SSH server, trigger out of bounds read and gain access to sensitive information or perform denial of service attack.
3) Out-of-bounds write (CVE-ID: CVE-2019-3863)
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a boundary error when processing total length of multiple keyboard interactive response messages that exceeds the value of unsigned char max characters. A remote attacker can trick the victim to connect to a malicious SSH server, trigger our of bounds write and execute arbitrary code on the system with privileges of the user, running the affected application.
4) Out-of-bounds read (CVE-ID: CVE-2019-3860)
The vulnerability allows a remote attacker to gain access to potentially sensitive information.
The vulnerability exists due to a boundary condition when processing SFTP packets. A remote attacker can trick the victim to connect to a malicious SSH server, trigger out-of-bounds read error and read contents of memory or crash the affected application.
5) Out-of-bounds read (CVE-ID: CVE-2019-3859)
The vulnerability allows a remote attacker to gain access to potentially sensitive information.
The vulnerability exists due to a boundary condition when processing packets in _libssh2_packet_require() and _libssh2_packet_requirev() functions. A remote attacker can trick the victim to connect to a malicious SSH server, trigger out-of-bounds read error and read contents of memory or crash the affected application.
6) Integer overflow (CVE-ID: CVE-2019-3856)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to integer overflow when parsing keyboard prompt requests. A remote attacker can trick the victim to connect to a malicious SSH server, trigger integer overflow and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
7) Integer overflow (CVE-ID: CVE-2019-3857)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to integer overflow when parsing SSH_MSG_CHANNEL_REQUEST packets. A remote attacker can trick the victim to connect to a malicious SSH server, trigger integer overflow and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
8) Out-of-bounds read (CVE-ID: CVE-2019-3858)
The vulnerability allows a remote attacker to gain access to potentially sensitive information.
The vulnerability exists due to a boundary condition when processing SFTP packets. A remote attacker can trick the victim to connect to a malicious SSH server, trigger out-of-bounds read error and read contents of memory or crash the affected application.
9) Integer overflow (CVE-ID: CVE-2019-3855)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to integer overflow in the _libssh2_transport_read() function in transport.cwhen processing packet_lengthvalues. A remote attacker can trick the victim to connect to a malicious SSH server, trigger integer overflow and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
Remediation
Install update from vendor's website.