CVE-2010-4345
CVE-2010-4345 is a security flaw in Exim, mail server software. Someone who already has a way in can use Exim to run their own code. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 25 Mar 2022.[1]
Exim is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff. Exim has published a fix or advice.
Description
CISA calls it a privilege escalation in Exim Exim. In its words: “Exim allows local users to gain privileges by leveraging the ability of the exim user account to specify an alternate configuration file with a directive that contains arbitrary commands.”[1]
The CVE record adds: “Exim 4.72 and earlier allows local users to gain privileges by leveraging the ability of the exim user account to specify an alternate configuration file with a directive that contains arbitrary commands, as demonstrated by the spool_directory directive.”[2]
The underlying weakness is permissions and access control (CWE-264), in MITRE’s list of common software weaknesses.
It scores 7.8 out of 10 on the Common Vulnerability Scoring System, which rates it high, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record doesn’t list version ranges for it; Exim’s advisory has them[3]. CISA names the product as Exim Exim.
Most families won’t have Exim; it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 25 Mar 2022, 4,119 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 15 Apr 2022 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 18%. That’s in the top 3% of the flaws it scores.[4]
CISA assesses it as not automatable: each attack takes some work.
CISA doesn’t say who was attacked, or how.
Fix
Exim has published a fix or advice.[3] CISA’s required action: “Apply updates per vendor instructions.”[1]
- Check whether you use it.Exim is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
- Send this page to your IT person.Ask them to confirm it’s fixed, or not in use. CISA gave US government agencies until 15 Apr 2022 to fix it.
- If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.
You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 7.8.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 18%.[4] |
See also
Other Exim flaws
- CVE-2010-4344: heap-based buffer overflow ·
- CVE-2018-6789: buffer overflow ·
Other Exim flaws
- CVE-2019-16928, Exim Internet Mailer: out-of-bounds write ·
- CVE-2019-10149, Exim Mail Transfer Agent (MTA): improper input validation ·
Other permissions and access control flaws
- CVE-2015-3246, Red Hat Libuser: race condition ·
- CVE-2013-0643, Adobe Flash Player: incorrect default permissions ·
- CVE-2016-0165, Microsoft Win32k: privilege escalation ·
- CVE-2015-6175, Microsoft Windows: kernel privilege escalation ·
- CVE-2015-1769, Microsoft Windows: mount manager privilege escalation ·
Added the same day
- CVE-2022-26318, WatchGuard Firebox and XTM Appliances: arbitrary code execution ·
- CVE-2022-26143, Mitel MiCollab, MiVoice Business Express: access control ·
- CVE-2022-21999, Microsoft Windows: print spooler privilege escalation ·
- CVE-2021-42237, Sitecore XP: remote command execution ·
- CVE-2021-22941, Citrix ShareFile: improper access control ·
Every Exim flaw on CISA’s list · Everything added in March 2022
References
- ^ Cybersecurity and Infrastructure Security Agency. “Exim Privilege Escalation Vulnerability”. Known Exploited Vulnerabilities Catalog, added 25 Mar 2022.
- ^ National Institute of Standards and Technology. “CVE-2010-4345 Detail”. National Vulnerability Database, published 14 Dec 2010.
- ^ Exim. Advisories and fixes: bugzilla.redhat.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.180, percentile 97.2, 31 Oct 2026.
- CVE Program. “CVE-2010-4345”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.