Out-of-bounds Read in Exim
CVE-2020-12783
Exim through 4.93 has an out-of-bounds read in the SPA authenticator that could result in SPA/NTLM authentication bypass in auths/spa.c and auths/auth-spa.c.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.046 (91.3th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 91st percentile — 91.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.046 · newest: 0.046 · change: 0.000
Affected products
- Exim
- Canonical Ubuntu Linux — versions 14.04, 16.04, 18.04
- Debian Linux — versions 8.0, 9.0, 10.0
- Fedoraproject Fedora — versions 31, 32
Weakness classification (CWE)
Public proof-of-concept exploits
References
- bugs.exim.org/show_bug.cgi (Third Party Advisory)
- git.exim.org/exim.git/commit/57aa14b216432be381b6295c312065b2fd034f86 (Patch, Third Party Advisory)
- git.exim.org/exim.git/commit/a04174dc2a84ae1008c23b6a7109e7fa3fb7b8b0 (Patch, Third Party Advisory)
- www.debian.org/security/2020/dsa-4687 (vendor-advisory, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2020/05/msg00017.html (mailing-list, Mailing List, Third Party Advisory)
- usn.ubuntu.com/4366-1/ (vendor-advisory, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- www.openwall.com/lists/oss-security/2021/05/04/7 (mailing-list, Exploit, Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2020-12783?
- CVE-2020-12783 is a high-severity vulnerability in Exim, classified under Out-of-bounds Read. CVSS score: 7.5/10. Published 2020-05-11.
- How severe is CVE-2020-12783?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2020-12783 known to be exploited?
- 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.