SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2015-2721

Mozilla Network Security Services (NSS) before 3.19, as used in Mozilla Firefox before 39.0, Firefox ESR 31.x before 31.8 and 38.x before 38.1, Thunderbird before 38.1, and other products, does not properly determine state transitions for the TLS state…

MEDIUM 4.3EPSS 3.28%

Does this matter?

Lower severity and a low EPSS score (3.28%). Track it; it rarely justifies an emergency change on its own.

Description

Mozilla Network Security Services (NSS) before 3.19, as used in Mozilla Firefox before 39.0, Firefox ESR 31.x before 31.8 and 38.x before 38.1, Thunderbird before 38.1, and other products, does not properly determine state transitions for the TLS state machine, which allows man-in-the-middle attackers to defeat cryptographic protection mechanisms by blocking messages, as demonstrated by removing a forward-secrecy property by blocking a ServerKeyExchange message, aka a "SMACK SKIP-TLS" issue.

CVSS 2.0
4.3 MEDIUMAV:N/AC:M/Au:N/C:N/I:P/A:N
EPSS
3.28% probability · 88th percentile
CISA KEV
Not listed
Weakness
CWE-310
Affected
novell/suse linux enterprise software development kit · canonical/ubuntu linux · debian/debian linux · novell/suse linux enterprise desktop · novell/suse linux enterprise server · mozilla/network security services · oracle/solaris · oracle/vm server
Source
security@mozilla.org

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.