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| author | Qualys Security Advisory <qsa@qualys.com> | 2021-02-21 21:26:53 -0800 |
|---|---|---|
| committer | Heiko Schlittermann (HS12-RIPE) <hs@schlittermann.de> | 2021-04-28 00:40:45 +0200 |
| commit | fcddccd650178ceeec3655c6c40f420164a8706e (patch) | |
| tree | bb88f538a423bc7218e2afcb7790f5cf27361bb6 | |
| parent | 4daba4bec729a57fb0863af786a1395e70794c76 (diff) | |
| download | exim4-fcddccd650178ceeec3655c6c40f420164a8706e.tar.gz | |
CVE-2020-28015+28021: New-line injection into spool header file
(cherry picked from commit 31b1a42d0bd29cb05f85e56d3343b13bef20a2bd)
| -rw-r--r-- | src/src/spool_out.c | 23 |
1 files changed, 18 insertions, 5 deletions
diff --git a/src/src/spool_out.c b/src/src/spool_out.c index 0851ce956..a0c69952c 100644 --- a/src/src/spool_out.c +++ b/src/src/spool_out.c @@ -105,6 +105,18 @@ return fd; +static const uschar * +zap_newlines(const uschar *s) +{ +uschar *z, *p; + +if (Ustrchr(s, '\n') == NULL) return s; + +p = z = string_copy(s); +while ((p = Ustrchr(p, '\n')) != NULL) *p++ = ' '; +return z; +} + static void spool_var_write(FILE * fp, const uschar * name, const uschar * val) { @@ -221,7 +233,7 @@ if (body_zerocount > 0) fprintf(fp, "-body_zerocount %d\n", body_zerocount); if (authenticated_id) spool_var_write(fp, US"auth_id", authenticated_id); if (authenticated_sender) - spool_var_write(fp, US"auth_sender", authenticated_sender); + spool_var_write(fp, US"auth_sender", zap_newlines(authenticated_sender)); if (f.allow_unqualified_recipient) fprintf(fp, "-allow_unqualified_recipient\n"); if (f.allow_unqualified_sender) fprintf(fp, "-allow_unqualified_sender\n"); @@ -294,19 +306,20 @@ fprintf(fp, "%d\n", recipients_count); for (int i = 0; i < recipients_count; i++) { recipient_item *r = recipients_list + i; + const uschar *address = zap_newlines(r->address); /* DEBUG(D_deliver) debug_printf("DSN: Flags: 0x%x\n", r->dsn_flags); */ if (r->pno < 0 && !r->errors_to && r->dsn_flags == 0) - fprintf(fp, "%s\n", r->address); + fprintf(fp, "%s\n", address); else { - uschar * errors_to = r->errors_to ? r->errors_to : US""; + const uschar *errors_to = r->errors_to ? zap_newlines(r->errors_to) : CUS""; /* for DSN SUPPORT extend exim 4 spool in a compatible way by adding new values upfront and add flag 0x02 */ - uschar * orcpt = r->orcpt ? r->orcpt : US""; + const uschar *orcpt = r->orcpt ? zap_newlines(r->orcpt) : CUS""; - fprintf(fp, "%s %s %d,%d %s %d,%d#3\n", r->address, orcpt, Ustrlen(orcpt), + fprintf(fp, "%s %s %d,%d %s %d,%d#3\n", address, orcpt, Ustrlen(orcpt), r->dsn_flags, errors_to, Ustrlen(errors_to), r->pno); } |