FreshPorts - VuXML

This vulnerability affects Exim instances built with DKIM enabled (this is the default for FreeBSD Exim port) and running verification of DKIM signatures on the incoming mail messages.

Phil Penncock reports:

This is a SECURITY release, addressing a CRITICAL remote code execution flaw in versions of Exim between 4.70 and 4.80 inclusive, when built with DKIM support (the default).

This security vulnerability can be exploited by anyone who can send email from a domain for which they control the DNS.

You are not vulnerable if you built Exim with DISABLE_DKIM or if you put this at the start of an ACL plumbed into acl_smtp_connect or acl_smtp_rcpt:

warn control = dkim_disable_verify

ge 4.70 lt 4.80.1

The Exim development team reports:

All installations having Exim set-uid root and using 'perl_startup' are vulnerable to a local privilege escalation. Any user who can start an instance of Exim (and this is normally any user) can gain root privileges. If you do not use 'perl_startup' you should be safe.

< 4.86.2

< 4.85.2

< 4.84.2

Exim developers report:

There is a buffer overflow in base64d(), if some pre-conditions are met. Using a handcrafted message, remote code execution seems to be possible.

< 4.90.1

The Exim project reports:

Exim leaks the private DKIM signing key to the log files. Additionally, if the build option EXPERIMENTAL_DSN_INFO=yes is used, the key material is included in the bounce message.

gt 4.69 lt 4.87.1

The Exim development team reports:

All installations having Exim set-uid root and using 'perl_startup' are vulnerable to a local privilege escalation. Any user who can start an instance of Exim (and this is normally any user) can gain root privileges. If you do not use 'perl_startup' you should be safe.

< 4.86.2

< 4.85.2

< 4.84.2

The Exim development team reports:

All installations having Exim set-uid root and using 'perl_startup' are vulnerable to a local privilege escalation. Any user who can start an instance of Exim (and this is normally any user) can gain root privileges. If you do not use 'perl_startup' you should be safe.

< 4.86.2

< 4.85.2

< 4.84.2

Exim developers report:

If your Exim server accepts TLS connections, it is vulnerable. This does not depend on the TLS libray, so both, GnuTLS and OpenSSL are affected.

The vulnerability is exploitable by sending a SNI ending in a backslash-null sequence during the initial TLS handshake. The exploit exists as a POC. For more details see the document qualys.mbx

< 4.92.2

Qualsys reports:

Exim supports the use of multiple "-p" command line arguments which are malloc()'ed and never free()'ed, used in conjunction with other issues allows attackers to cause arbitrary code execution. This affects exim version 4.89 and earlier. Please note that at this time upstream has released a patch (commit 65e061b76867a9ea7aeeb535341b790b90ae6c21), but it is not known if a new point release is available that addresses this issue at this time.

< 4.89_1