OpenSSH up to 5.x/6.x/7.1p1 Forward Option roaming_common.c roaming_read/roaming_write memory corruption

CVSS Meta Temp Score
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CTI Interest Score
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7.8$0-$5k0.00

Summaryinfo

A vulnerability was found in OpenSSH up to 5.x/6.x/7.1p1. It has been classified as critical. Affected by this vulnerability is the function roaming_read/roaming_write of the file roaming_common.c of the component Forward Option Handler. The manipulation leads to memory corruption. This vulnerability is uniquely identified as CVE-2016-0778. The attack is possible to be carried out remotely. No exploit exists. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in OpenSSH up to 5.x/6.x/7.1p1 (Connectivity Software) and classified as critical. This issue affects the function roaming_read/roaming_write of the file roaming_common.c of the component Forward Option Handler. The manipulation with an unknown input leads to a memory corruption vulnerability. Using CWE to declare the problem leads to CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

The (1) roaming_read and (2) roaming_write functions in roaming_common.c in the client in OpenSSH 5.x, 6.x, and 7.x before 7.1p2, when certain proxy and forward options are enabled, do not properly maintain connection file descriptors, which allows remote servers to cause a denial of service (heap-based buffer overflow) or possibly have unspecified other impact by requesting many forwardings.

The weakness was disclosed 01/14/2016 with Qualys as confirmed mailinglist post (oss-sec). It is possible to read the advisory at seclists.org. The identification of this vulnerability is CVE-2016-0778 since 12/16/2015. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit.

We expect the 0-day to have been worth approximately $25k-$100k. The vulnerability scanner Nessus provides a plugin with the ID 87972 (Amazon Linux AMI : openssh (ALAS-2016-638)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Amazon Linux Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 350064 (Amazon Linux Security Advisory for openssh: ALAS-2016-638).

Upgrading to version 7.1p2 eliminates this vulnerability. A possible mitigation has been published 4 days after the disclosure of the vulnerability. Furthermore it is possible to detect and prevent this kind of attack with TippingPoint and the filter 22609.

The vulnerability is also documented in the databases at X-Force (109636), Tenable (87972), SecurityFocus (BID 80698†) and Vulnerability Center (SBV-55704†). The entries VDB-80266, VDB-80330, VDB-81465 and VDB-81466 are pretty similar. Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.1
VulDB Meta Temp Score: 7.8

VulDB Base Score: 8.1
VulDB Temp Score: 7.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 8.1
NVD Vector: 🔍

ADP CISA Base Score: 8.1
ADP CISA Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Memory corruption
CWE: CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Unproven

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 87972
Nessus Name: Amazon Linux AMI : openssh (ALAS-2016-638)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 703446
OpenVAS Name: Debian Security Advisory DSA 3446-1 (openssh - security update)
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Upgrade: OpenSSH 7.1p2
TippingPoint: 🔍

McAfee IPS: 🔍
McAfee IPS Version: 🔍

Fortigate IPS: 🔍

Timelineinfo

12/16/2015 🔍
01/14/2016 +29 days 🔍
01/14/2016 +0 days 🔍
01/14/2016 +0 days 🔍
01/14/2016 +0 days 🔍
01/15/2016 +1 days 🔍
01/15/2016 +0 days 🔍
01/18/2016 +3 days 🔍
01/19/2016 +1 days 🔍
05/29/2026 +3783 days 🔍

Sourcesinfo

Advisory: USN-2869-1
Organization: Qualys
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2016-0778 (🔍)
GCVE (CVE): GCVE-0-2016-0778
GCVE (VulDB): GCVE-100-80267

OVAL: 🔍

X-Force: 109636 - OpenSSH packet_write_wait() and ssh_packet_write_wait() buffer overflow
SecurityFocus: 80698 - OpenSSH CVE-2016-0778 Heap Based Buffer Overflow Vulnerability
SecurityTracker: 1034671
Vulnerability Center: 55704 - OpenSSH Remote DoS due to Improper Connection Maintenance of File Descriptors, Low

See also: 🔍

Entryinfo

Created: 01/15/2016 09:33
Updated: 05/29/2026 23:40
Changes: 01/15/2016 09:33 (73), 06/21/2018 09:03 (26), 07/03/2022 13:19 (4), 05/29/2026 23:40 (25)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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