Integer overflow in Openssl

CVE-2019-1551

There is an overflow bug in the x64_64 Montgomery squaring procedure used in exponentiation with 512-bit moduli. No EC algorithms are affected. Analysis suggests that attacks against 2-prime RSA1024, 3-prime RSA1536, and DSA1024 as a result of this defect would be very difficult to perform and are not believed likely. Attacks against DH512 are considered just feasible. However, for an attack the target would have to re-use the DH512 private key, which is not recommended anyway. Also applications directly using the low level API BN_mod_exp may be affected if they use BN_FLG_CONSTTIME. Fixed in OpenSSL 1.1.1e (Affected 1.1.1-1.1.1d). Fixed in OpenSSL 1.0.2u (Affected 1.0.2-1.0.2t).

Vulnerability class: Integer Overflow

EPSS: 0.143 (96.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2019-1551?
CVE-2019-1551 is a medium-severity vulnerability in Openssl, classified under Integer Overflow or Wraparound. CVSS score: 5.3/10. Published 2019-12-06.
How severe is CVE-2019-1551?
Medium severity. CVSS v3 base score is 5.3 out of 10.
Is CVE-2019-1551 known to be exploited?
17 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.