Every CVE Search/ Get API key

CVE-2017-3733

Encrypt-Then-Mac renegotiation crash

7.5 HighFix available

CVE-2017-3733 is a high vulnerability (CVSS 7.5) in Openssl, published May 4, 2017. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 12.9%, the 96th percentile. Fixed in openssl 1.1.0e-1.

During a renegotiation handshake if the Encrypt-Then-Mac extension is negotiated where it was not in the original handshake (or vice-versa) then this can cause OpenSSL 1.1.0 before 1.1.0e to crash (dependent on ciphersuite). Both clients and servers are affected.

Attack profile

How easy it is to exploit

Attack vector
Network
Complexity
Low
Privileges needed
None
User interaction
None

What an attacker can affect

Confidentiality
None
Integrity
None
Availability
High

Exploit likelihood

12.9%Up 4.1 points since Apr 14, 2021
90%50%10%1%

What each source reports

NVD Score used 7.5

During a renegotiation handshake if the Encrypt-Then-Mac extension is negotiated where it was not in the original handshake (or vice-versa) then this can cause OpenSSL 1.1.0 before 1.1.0e to crash (dependent on ciphersuite). Both clients and servers are affected.

Record
CVE-2017-3733
CVSS 3.0
7.5 HighCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0
5.0 MediumAV:N/AC:L/Au:N/C:N/I:N/A:P
Weakness
CWE-20
Updated
2026-11-02
CVE List No score

Encrypt-Then-Mac renegotiation crash

During a renegotiation handshake if the Encrypt-Then-Mac extension is negotiated where it was not in the original handshake (or vice-versa) then this can cause OpenSSL 1.1.0 before 1.1.0e to crash (dependent on ciphersuite). Both clients and servers are affected.

Record
CVE-2017-3733
Updated
2026-11-02
EUVDEUVD-2017-12850 No score

During a renegotiation handshake if the Encrypt-Then-Mac extension is negotiated where it was not in the original handshake (or vice-versa) then this can cause OpenSSL 1.1.0 before 1.1.0e to crash (dependent on ciphersuite). Both clients and servers are affected.

Record
EUVD-2017-12850
Updated
2026-11-03
GitHub AdvisoriesGHSA-6553-6v42-5wqc 7.5

During a renegotiation handshake if the Encrypt-Then-Mac extension is negotiated where it was not...

During a renegotiation handshake if the Encrypt-Then-Mac extension is negotiated where it was not in the original handshake (or vice-versa) then this can cause OpenSSL 1.1.0 before 1.1.0e to crash (dependent on ciphersuite). Both clients and servers are affected.

Record
GHSA-6553-6v42-5wqc
CVSS 3.0
7.5 HighCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness
CWE-20
Updated
2026-11-02
OSV 7.5

During a renegotiation handshake if the Encrypt-Then-Mac extension is negotiated where it was not in the original handshake (or vice-versa) then this can cause OpenSSL 1.1.0 before 1.1.0e to crash (dependent on ciphersuite). Both clients and servers are affected.

Record
CVE-2017-3733
CVSS 3.0
7.5 HighCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated
2026-11-02
OSVDEBIAN-CVE-2017-3733 7.5

During a renegotiation handshake if the Encrypt-Then-Mac extension is negotiated where it was not in the original handshake (or vice-versa) then this can cause OpenSSL 1.1.0 before 1.1.0e to crash (dependent on ciphersuite). Both clients and servers are affected.

Record
DEBIAN-CVE-2017-3733
CVSS 3.0
7.5 HighCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated
2026-11-02
OSVUBUNTU-CVE-2017-3733 7.5

During a renegotiation handshake if the Encrypt-Then-Mac extension is negotiated where it was not in the original handshake (or vice-versa) then this can cause OpenSSL 1.1.0 before 1.1.0e to crash (dependent on ciphersuite). Both clients and servers are affected.

Record
UBUNTU-CVE-2017-3733
CVSS 3.0
7.5 HighCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated
2026-11-02
OSVMGASA-2017-0390 No score

Updated virtualbox packages fix security vulnerabilities

This update provides the virtualbox 5.1.30 maintenance release, fixing security and other issues:

In OpenSSL 1.1.0 before 1.1.0d, if a malicious server supplies bad parameters for a DHE or ECDHE key exchange then this can result in the client attempting to dereference a NULL pointer leading to a client crash. This could be exploited in a Denial of Service attack (CVE-2017-3730).

OpenSSL is vulnerable to a denial of service, caused by an out-of-bounds read when using a specific cipher. By sending specially crafted truncated packets, a remote attacker could exploit this vulnerability using CHACHA20/POLY1305 to cause the application to crash (CVE-2017-3731).

OpenSSL could allow a remote attacker to obtain sensitive information, caused by a propagation error in the BN_mod_exp() function. An attacker could exploit this vulnerability to obtain information about the private key (CVE-2017-3732).

During a renegotiation handshake if the Encrypt-Then-Mac extension is negotiated where it was not in the original handshake (or vice-versa) then this can cause OpenSSL 1.1.0 before 1.1.0e to crash (dependent on ciphersuite). Both clients and servers are affected (CVE-2017-3733)

A local user can exploit a flaw in the Oracle VM VirtualBox Core component to partially access data, partially modify data, and deny service (CVE-2017-10392, CVE-2017-10407, CVE-2017-10408).

A local user can exploit a flaw in the Oracle VM VirtualBox Core component to partially access data, partially modify data, and partially deny service (CVE-2017-10428).

For other fixes in this update see the referenced changelog.

Record
MGASA-2017-0390
Updated
2026-11-02

Affected products

Affected packages

Affected packages
PackageAffectedFixed
openssl
Debian:12
before 1.1.0e-1
1.1.0e-1
openssl
Debian:13
before 1.1.0e-1
1.1.0e-1
openssl
Debian:14
before 1.1.0e-1
1.1.0e-1
virtualbox
Mageia:5
before 5.1.30-1.mga5
5.1.30-1.mga5
kmod-vboxadditions
Mageia:5
before 5.1.30-1.mga5
5.1.30-1.mga5
kmod-virtualbox
Mageia:5
before 5.1.30-1.mga5
5.1.30-1.mga5
virtualbox
Mageia:6
before 5.1.30-1.mga6
5.1.30-1.mga6
kmod-vboxadditions
Mageia:6
before 5.1.30-1.mga6
5.1.30-1.mga6
kmod-virtualbox
Mageia:6
before 5.1.30-1.mga6
5.1.30-1.mga6

History

History
WhenChangedSources
2026-11-03affected
2026-11-03aliasesEUVD
2026-11-02createdCVE List, GitHub Advisories, NVD, OSV

References

Show 10 moreShow less
MoveEnter Open