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| author | Rainer Gerhards <rgerhards@adiscon.com> | 2008-12-04 14:09:38 +0100 |
|---|---|---|
| committer | Rainer Gerhards <rgerhards@adiscon.com> | 2008-12-04 14:09:38 +0100 |
| commit | afdccceefa30306cf720a27efd5a29bcc5a916c9 (patch) | |
| tree | 0d2e52ccfe2db3a8802b6c06a0beae0967bf276e /plugins | |
| parent | d74b4fef35e8a2c3a58fe66720840ae2ee77a02d (diff) | |
| download | rsyslog-afdccceefa30306cf720a27efd5a29bcc5a916c9.tar.gz rsyslog-afdccceefa30306cf720a27efd5a29bcc5a916c9.tar.xz rsyslog-afdccceefa30306cf720a27efd5a29bcc5a916c9.zip | |
security fix: imudp emitted a message when a non-permitted sender...v3.20.2
...tried to send a message to it. This behaviour is operator-configurable.
If enabled, a message was emitted each time. That way an attacker could
effectively fill the disk via this facility. The message is now
emitted only once in a minute (this currently is a hard-coded limit,
if someone comes up with a good reason to make it configurable, we
will probably do that).
Diffstat (limited to 'plugins')
| -rw-r--r-- | plugins/imudp/imudp.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/plugins/imudp/imudp.c b/plugins/imudp/imudp.c index 57c5c02d..b18c0db7 100644 --- a/plugins/imudp/imudp.c +++ b/plugins/imudp/imudp.c @@ -51,6 +51,10 @@ DEFobjCurrIf(errmsg) DEFobjCurrIf(glbl) DEFobjCurrIf(net) +static time_t ttLastDiscard = 0; /* timestamp when a message from a non-permitted sender was last discarded + * This shall prevent remote DoS when the "discard on disallowed sender" + * message is configured to be logged on occurance of such a case. + */ static int *udpLstnSocks = NULL; /* Internet datagram sockets, first element is nbr of elements * read-only after init(), but beware of restart! */ static uchar *pszBindAddr = NULL; /* IP to bind socket to */ @@ -199,8 +203,15 @@ CODESTARTrunInput } else { dbgprintf("%s is not an allowed sender\n", (char*)fromHostFQDN); if(glbl.GetOption_DisallowWarning) { - errmsg.LogError(0, NO_ERRCODE, "UDP message from disallowed sender %s discarded", - (char*)fromHost); + time_t tt; + + time(&tt); + if(tt > ttLastDiscard + 60) { + ttLastDiscard = tt; + errmsg.LogError(0, NO_ERRCODE, + "UDP message from disallowed sender %s discarded", + (char*)fromHost); + } } } } |